[libc++] Fix __bitop_unsigned_integer, rename to __is_unsigned_integer, and fix constexprness of std::countr_zero(__uint128_t)

[• Quuxplusone]

Summary

Fixes https://bugs.llvm.org/show_bug.cgi?id=49450

There are only five unsigned integer types, so we should just list them out.
Also provide `__is_signed_integer`, even though the Standard doesn't consume
that trait anywhere yet.

Notice that `concept uniform_random_bit_generator` is specifically specified
to rely on `concept unsigned_integral` and *not* `__is_unsigned_integer`.
Instantiating `std::ranges::sample` with a type `U` satisfying
`uniform_random_bit_generator` where `unsigned_integral<U::result_type>`
and not `__is_unsigned_integer<U::result_type>` is simply IFNDR.

Also vastly improve test coverage for the <bit> manipulation functions, using our modern "test runtime and constexpr-time with the same function" approach.

[• Quuxplusone]

libcxx/include/bit

79–80

Seems like we should add char8_t while we're here, yeah? (It is also integral and unsigned but not an unsigned integer type.) For bonus clarity, we could make a type trait __is_integer_type<_Tp> and then this whole constraint on line 97 would be simply

static_assert(__is_integer_type<_Tp>::value && is_unsigned<_Tp>::value, "__rotl requires an unsigned integer type");

...except that a static_assert is not a "constraint," so we're just totally nonconforming here.
@jwakely, thoughts? I'd volunteer to commandeer if you like.

[jwakely]

libcxx/include/bit

79–80

Yes, that should be there too. Feel free to take this, I only submitted it here because it seemed better to put the patch here than in bugzilla.

[• Quuxplusone]

libcxx/include/bit

79–80

Blech.
@mclow.lists, @ldionne: libc++ currently supports __uint128_t for these functions; do we want to keep supporting it?
libstdc++ does not support it: https://godbolt.org/z/jK9q8z6oT

I'm going to operate on the assumption that we want to keep it (as a non-conforming extension)...

[jwakely]

libcxx/include/bit

79–80

If you want non-conforming extensions then you need to compile with -std=gnu++20 not -std=c++20 and if you do that, libstdc++ does support unsigned __int128 here.

[jwakely]

libcxx/include/bit

79–80

The static assert is not a problem, because you're only looking at the internal __rotl function which doesn't need to be constrained. The public rotl function is constrained correctly, using enable_if.

[• Quuxplusone]

libcxx/include/bit

84

I relaxed the static_assert on the internal functions for the same (bad) intuitive reason that the internal functions are provided in the first place. We never actually use any of these internal functions, but if we did, it might be nice to be able to use them on, I dunno, char or something. I'm highly ambivalent about whether we should be asserting anything at all, or if we do, what it should be. So I'll take suggestions if anyone's got any.

119–125

This is a bugfix: std::countr_zero(__uint128_t(1) << 64) had been trying to evaluate __libcpp_ctz(0uLL) in constexpr context, and that's not allowed. The old tests didn't catch it but the new tests do.

[jwakely]

FWIW

libcxx/include/bit

84

FWIW libstdc++ has similar internal versions of these functions, available from C++14 up, and I didn't constrain them or add assertions. The public functions are responsible for input validation (if needed) and the internal functions assume the caller knows what they're doing.

[• Quuxplusone]

Not sure what happened with https://buildkite.com/llvm-project/libcxx-ci/builds/3210 . Rebase and poke buildkite; let's see if buildkite fixed itself.

[• Quuxplusone]

Okay, what if we don't rearrange the order in which <bit> includes <__debug>?
(I'm preparing another patch to just alphabetize all the includes everywhere.)

[• Quuxplusone]

Well, I don't know what's throwing bad_cast from inside the regex code, so let's just poke buildkite with something totally innocuous for now and see what happens.
https://buildkite.com/llvm-project/libcxx-ci/builds/3225

[• Quuxplusone]

Okay, 92260d7a186425510e96b7036b467a6889d08d97 reverted the thing that was probably breaking all the tests. Let's try buildkite again.

[tschuett]

In D102328#2755987, @Quuxplusone wrote:

Okay, what if we don't rearrange the order in which <bit> includes <__debug>?
(I'm preparing another patch to just alphabetize all the includes everywhere.)

clang-format has

SortIncludes, IncludeCategories, and IncludeBlocks

[Mordante]

LGTM, with a few suggestions.

libcxx/include/type_traits

816

How do you feel about using __libcpp_is_signed_integer to match the __libcpp_is_floating_point below?

libcxx/test/std/numerics/bit/bit.pow.two/bit_ceil.pass.cpp

60

What about removing this function and add it to the generic test and use it in a if constexpr(std::same_as<T, __uint128_t>) block?
(Obviously still guarded by`#ifndef _LIBCPP_HAS_NO_INT128`)

[• Quuxplusone]

libcxx/include/type_traits

816

I wasn't sure what the convention is here. It looks like we can't use e.g. __is_floating_point because that's sometimes a builtin, so we use __libcpp_is_floating_point instead? In this case __is_signed_integer isn't a builtin — well, isn't one today — but yeah, I guess on this second glance I am coming around to naming this entrypoint with a leading __libcpp_. That way, if it ever becomes a builtin, we won't have to change its call-sites.

libcxx/test/std/numerics/bit/bit.pow.two/bit_ceil.pass.cpp

60

Part of my thinking here was that these tests could be ported over into libcxx/test/libcxx/ to test std::__bit_ceil and so on, in pre-'17 language modes, so we want to keep avoiding if constexpr.
But clearly I didn't actually do that porting-over; and I did remove the trailing ,"" from all the static_asserts; so I guess it'd be okay to move this into test(). It would make the file a bit shorter. Will do, or at least consider.

[• Quuxplusone]

Take @Mordante's review comments; poke buildbot with some header-alphabetization NFC too.

libcxx/include/bit

 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-
-template <class _Tp>
-using __bitop_unsigned_integer _LIBCPP_NODEBUG_TYPE = integral_constant<bool,
-         is_integral<_Tp>::value &&
-         is_unsigned<_Tp>::value &&
-        _IsNotSame<typename remove_cv<_Tp>::type, bool>::value &&
-        _IsNotSame<typename remove_cv<_Tp>::type, signed char>::value &&
-        _IsNotSame<typename remove_cv<_Tp>::type, wchar_t>::value &&
-        _IsNotSame<typename remove_cv<_Tp>::type, char16_t>::value &&
-        _IsNotSame<typename remove_cv<_Tp>::type, char32_t>::value
-    >;
-
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _Tp __rotl(_Tp __t, unsigned int __cnt) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__rotl requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__rotl requires an unsigned integer type");
     const unsigned int __dig = numeric_limits<_Tp>::digits;
     if ((__cnt % __dig) == 0)
         return __t;
     return (__t << (__cnt % __dig)) | (__t >> (__dig - (__cnt % __dig)));
 }
 
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _Tp __rotr(_Tp __t, unsigned int __cnt) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__rotr requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__rotr requires an unsigned integer type");
     const unsigned int __dig = numeric_limits<_Tp>::digits;
     if ((__cnt % __dig) == 0)
         return __t;
     return (__t >> (__cnt % __dig)) | (__t << (__dig - (__cnt % __dig)));
 }
 
-
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 int __countr_zero(_Tp __t) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__countr_zero requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__countr_zero requires an unsigned integer type");
     if (__t == 0)
         return numeric_limits<_Tp>::digits;
 
     if      (sizeof(_Tp) <= sizeof(unsigned int))
         return __libcpp_ctz(static_cast<unsigned int>(__t));
     else if (sizeof(_Tp) <= sizeof(unsigned long))
         return __libcpp_ctz(static_cast<unsigned long>(__t));
     else if (sizeof(_Tp) <= sizeof(unsigned long long))
         return __libcpp_ctz(static_cast<unsigned long long>(__t));
     else
     {
         int __ret = 0;
-        int __iter = 0;
         const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
-        while ((__iter = __libcpp_ctz(static_cast<unsigned long long>(__t))) == __ulldigits)
+        while (static_cast<unsigned long long>(__t) == 0uLL)
         {
-            __ret += __iter;
+            __ret += __ulldigits;
             __t >>= __ulldigits;
         }
-        return __ret + __iter;
+        return __ret + __libcpp_ctz(static_cast<unsigned long long>(__t));
     }
 }
 
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 int __countl_zero(_Tp __t) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__countl_zero requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__countl_zero requires an unsigned integer type");
     if (__t == 0)
         return numeric_limits<_Tp>::digits;
 
     if      (sizeof(_Tp) <= sizeof(unsigned int))
         return __libcpp_clz(static_cast<unsigned int>(__t))
               - (numeric_limits<unsigned int>::digits - numeric_limits<_Tp>::digits);
     else if (sizeof(_Tp) <= sizeof(unsigned long))
         return __libcpp_clz(static_cast<unsigned long>(__t))
else
         return __ret + __iter;
     }
 }
 
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 int __countl_one(_Tp __t) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__countl_one requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__countl_one requires an unsigned integer type");
     return __t != numeric_limits<_Tp>::max()
         ? __countl_zero(static_cast<_Tp>(~__t))
         : numeric_limits<_Tp>::digits;
 }
 
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 int __countr_one(_Tp __t) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__countr_one requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__countr_one requires an unsigned integer type");
     return __t != numeric_limits<_Tp>::max()
         ? __countr_zero(static_cast<_Tp>(~__t))
         : numeric_limits<_Tp>::digits;
 }
 
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-int
-__popcount(_Tp __t) _NOEXCEPT
+int __popcount(_Tp __t) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__libcpp_popcount requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__popcount requires an unsigned integer type");
     if      (sizeof(_Tp) <= sizeof(unsigned int))
         return __libcpp_popcount(static_cast<unsigned int>(__t));
     else if (sizeof(_Tp) <= sizeof(unsigned long))
         return __libcpp_popcount(static_cast<unsigned long>(__t));
     else if (sizeof(_Tp) <= sizeof(unsigned long long))
         return __libcpp_popcount(static_cast<unsigned long long>(__t));
     else
     {
         int __ret = 0;
         while (__t != 0)
         {
             __ret += __libcpp_popcount(static_cast<unsigned long long>(__t));
             __t >>= numeric_limits<unsigned long long>::digits;
         }
         return __ret;
     }
 }
 
-
 // integral log base 2
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 unsigned __bit_log2(_Tp __t) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__bit_log2 requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__bit_log2 requires an unsigned integer type");
     return numeric_limits<_Tp>::digits - 1 - __countl_zero(__t);
 }
 
 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
 bool __has_single_bit(_Tp __t) _NOEXCEPT
 {
-    static_assert(__bitop_unsigned_integer<_Tp>::value, "__has_single_bit requires unsigned");
+    static_assert(is_unsigned<_Tp>::value, "__has_single_bit requires an unsigned integer type");
     return __t != 0 && (((__t & (__t - 1)) == 0));
 }
 
-
 #if _LIBCPP_STD_VER > 17
 
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+_EnableIf<__is_unsigned_integer<_Tp>::value, _Tp>
 rotl(_Tp __t, unsigned int __cnt) noexcept
 {
     return __rotl(__t, __cnt);
 }
 
-
-// rotr
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+_EnableIf<__is_unsigned_integer<_Tp>::value, _Tp>
 rotr(_Tp __t, unsigned int __cnt) noexcept
 {
     return __rotr(__t, __cnt);
 }
 
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+_EnableIf<__is_unsigned_integer<_Tp>::value, int>
 countl_zero(_Tp __t) noexcept
 {
     return __countl_zero(__t);
 }
 
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+_EnableIf<__is_unsigned_integer<_Tp>::value, int>
 countl_one(_Tp __t) noexcept
 {
     return __countl_one(__t);
 }
 
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+_EnableIf<__is_unsigned_integer<_Tp>::value, int>
 countr_zero(_Tp __t) noexcept
 {
     return __countr_zero(__t);
 }
 
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+_EnableIf<__is_unsigned_integer<_Tp>::value, int>
 countr_one(_Tp __t) noexcept
 {
     return __countr_one(__t);
 }
 
-
 template<class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, int>
+_EnableIf<__is_unsigned_integer<_Tp>::value, int>
 popcount(_Tp __t) noexcept
 {
     return __popcount(__t);
 }
 
-
 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, bool>
+_EnableIf<__is_unsigned_integer<_Tp>::value, bool>
 has_single_bit(_Tp __t) noexcept
 {
     return __has_single_bit(__t);
 }
 
 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+_EnableIf<__is_unsigned_integer<_Tp>::value, _Tp>
 bit_floor(_Tp __t) noexcept
 {
     return __t == 0 ? 0 : _Tp{1} << __bit_log2(__t);
 }
 
 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+_EnableIf<__is_unsigned_integer<_Tp>::value, _Tp>
 bit_ceil(_Tp __t) noexcept
 {
     if (__t < 2) return 1;
     const unsigned __n = numeric_limits<_Tp>::digits - countl_zero((_Tp)(__t - 1u));
     _LIBCPP_DEBUG_ASSERT(__libcpp_is_constant_evaluated() || __n != numeric_limits<_Tp>::digits, "Bad input to bit_ceil");
 
     if constexpr (sizeof(_Tp) >= sizeof(unsigned))
         return _Tp{1} << __n;
     else
     {
         const unsigned __extra = numeric_limits<unsigned>::digits  - numeric_limits<_Tp>::digits;
         const unsigned __retVal = 1u << (__n + __extra);
         return (_Tp) (__retVal >> __extra);
     }
 }
 
 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<__bitop_unsigned_integer<_Tp>::value, _Tp>
+_EnableIf<__is_unsigned_integer<_Tp>::value, _Tp>
 bit_width(_Tp __t) noexcept
 {
     return __t == 0 ? 0 : __bit_log2(__t) + 1;
 }
 
 enum class endian
 {
     little = 0xDEAD,

libcxx/include/type_traits

 #if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
 template <class _Tp>
 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_integral_v
     = is_integral<_Tp>::value;
 #endif
 
 #endif // __has_keyword(__is_integral)
 
+// __is_signed_integer, __is_unsigned_integer
+
+// [basic.fundamental] defines five standard signed integer types;
+// __int128_t is an extended signed integer type.
+// The signed and unsigned integer types, plus bool and the
+// five types with "char" in their name, compose the "integral" types.
+
+template <class _Tp> struct __is_signed_integer : public false_type {};
+template <> struct __is_signed_integer<signed char>      : public true_type {};
+template <> struct __is_signed_integer<signed short>     : public true_type {};
+template <> struct __is_signed_integer<signed int>       : public true_type {};
+template <> struct __is_signed_integer<signed long>      : public true_type {};
+template <> struct __is_signed_integer<signed long long> : public true_type {};
+#ifndef _LIBCPP_HAS_NO_INT128
+template <> struct __is_signed_integer<__int128_t>       : public true_type {};
+#endif
+
+template <class _Tp> struct __is_unsigned_integer : public false_type {};
+template <> struct __is_unsigned_integer<unsigned char>      : public true_type {};
+template <> struct __is_unsigned_integer<unsigned short>     : public true_type {};
+template <> struct __is_unsigned_integer<unsigned int>       : public true_type {};
+template <> struct __is_unsigned_integer<unsigned long>      : public true_type {};
+template <> struct __is_unsigned_integer<unsigned long long> : public true_type {};
+#ifndef _LIBCPP_HAS_NO_INT128
+template <> struct __is_unsigned_integer<__uint128_t>        : public true_type {};
+#endif
+
 // is_floating_point
 
 template <class _Tp> struct __libcpp_is_floating_point              : public false_type {};
 template <>          struct __libcpp_is_floating_point<float>       : public true_type {};
 template <>          struct __libcpp_is_floating_point<double>      : public true_type {};
 template <>          struct __libcpp_is_floating_point<long double> : public true_type {};
 
 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_floating_point

libcxx/test/std/numerics/bit/bit.pow.two/bit_ceil.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr T bit_ceil(T x) noexcept;
 
+// Constraints: T is an unsigned integer type
 // Returns: The minimal value y such that has_single_bit(y) is true and y >= x;
 //    if y is not representable as a value of type T, the result is an unspecified value.
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
-{
-    return std::bit_ceil(T(0)) == T(1)
-       &&  std::bit_ceil(T(1)) == T(1)
-       &&  std::bit_ceil(T(2)) == T(2)
-       &&  std::bit_ceil(T(3)) == T(4)
-       &&  std::bit_ceil(T(4)) == T(4)
-       &&  std::bit_ceil(T(5)) == T(8)
-       &&  std::bit_ceil(T(6)) == T(8)
-       &&  std::bit_ceil(T(7)) == T(8)
-       &&  std::bit_ceil(T(8)) == T(8)
-       &&  std::bit_ceil(T(9)) == T(16)
-       ;
-}
-
-
-template <typename T>
-void runtime_test()
+template <class T>
+constexpr bool test()
 {
-    ASSERT_SAME_TYPE(T, decltype(std::bit_ceil(T(0))));
-    LIBCPP_ASSERT_NOEXCEPT(      std::bit_ceil(T(0)));
+    ASSERT_SAME_TYPE(decltype(std::bit_ceil(T())), T);
+    LIBCPP_ASSERT_NOEXCEPT(std::bit_ceil(T()));
 
-    assert( std::bit_ceil(T(60)) == T( 64));
-    assert( std::bit_ceil(T(61)) == T( 64));
-    assert( std::bit_ceil(T(62)) == T( 64));
-    assert( std::bit_ceil(T(63)) == T( 64));
-    assert( std::bit_ceil(T(64)) == T( 64));
-    assert( std::bit_ceil(T(65)) == T(128));
-    assert( std::bit_ceil(T(66)) == T(128));
-    assert( std::bit_ceil(T(67)) == T(128));
-    assert( std::bit_ceil(T(68)) == T(128));
-    assert( std::bit_ceil(T(69)) == T(128));
+    assert(std::bit_ceil(T(0)) == T(1));
+    assert(std::bit_ceil(T(1)) == T(1));
+    assert(std::bit_ceil(T(2)) == T(2));
+    assert(std::bit_ceil(T(3)) == T(4));
+    assert(std::bit_ceil(T(4)) == T(4));
+    assert(std::bit_ceil(T(5)) == T(8));
+    assert(std::bit_ceil(T(6)) == T(8));
+    assert(std::bit_ceil(T(7)) == T(8));
+    assert(std::bit_ceil(T(8)) == T(8));
+    assert(std::bit_ceil(T(9)) == T(16));
+    assert(std::bit_ceil(T(60)) == T(64));
+    assert(std::bit_ceil(T(61)) == T(64));
+    assert(std::bit_ceil(T(62)) == T(64));
+    assert(std::bit_ceil(T(63)) == T(64));
+    assert(std::bit_ceil(T(64)) == T(64));
+    assert(std::bit_ceil(T(65)) == T(128));
+    assert(std::bit_ceil(T(66)) == T(128));
+    assert(std::bit_ceil(T(67)) == T(128));
+    assert(std::bit_ceil(T(68)) == T(128));
+    assert(std::bit_ceil(T(69)) == T(128));
+
+    return true;
 }
 
-int main(int, char**)
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
+    __uint128_t val = 168;
+    __uint128_t ceil = 256;
+
+    assert(std::bit_ceil(val) == ceil);
+    assert(std::bit_ceil(val << 32) == (ceil << 32));
+    assert(std::bit_ceil((val << 64) | 0x1) == (ceil << 64));
+    assert(std::bit_ceil((val << 72) | 0x1) == (ceil << 72));
+    assert(std::bit_ceil((val << 100) | 0x1) == (ceil << 100));
+
+    return true;
+}
+#endif
 
+int main(int, char**)
+{
     {
     auto lambda = [](auto x) -> decltype(std::bit_ceil(x)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-    static_assert(constexpr_test<unsigned char>(),      "");
-    static_assert(constexpr_test<unsigned short>(),     "");
-    static_assert(constexpr_test<unsigned>(),           "");
-    static_assert(constexpr_test<unsigned long>(),      "");
-    static_assert(constexpr_test<unsigned long long>(), "");
-
-    static_assert(constexpr_test<uint8_t>(),   "");
-    static_assert(constexpr_test<uint16_t>(),  "");
-    static_assert(constexpr_test<uint32_t>(),  "");
-    static_assert(constexpr_test<uint64_t>(),  "");
-    static_assert(constexpr_test<size_t>(),    "");
-    static_assert(constexpr_test<uintmax_t>(), "");
-    static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
-
-    runtime_test<unsigned char>();
-    runtime_test<unsigned>();
-    runtime_test<unsigned short>();
-    runtime_test<unsigned long>();
-    runtime_test<unsigned long long>();
-
-    runtime_test<uint8_t>();
-    runtime_test<uint16_t>();
-    runtime_test<uint32_t>();
-    runtime_test<uint64_t>();
-    runtime_test<size_t>();
-    runtime_test<uintmax_t>();
-    runtime_test<uintptr_t>();
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
+#ifndef _LIBCPP_HAS_NO_INT128
+    test<__uint128_t>();
+#endif
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
 #ifndef _LIBCPP_HAS_NO_INT128
-    runtime_test<__uint128_t>();
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }

libcxx/test/std/numerics/bit/bit.pow.two/bit_floor.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr T bit_floor(T x) noexcept;
 
+// Constraints: T is an unsigned integer type
 // Returns: If x == 0, 0; otherwise the maximal value y such that bit_floor(y) is true and y <= x.
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-  return std::bit_floor(T(0)) == T(0)
-     &&  std::bit_floor(T(1)) == T(1)
-     &&  std::bit_floor(T(2)) == T(2)
-     &&  std::bit_floor(T(3)) == T(2)
-     &&  std::bit_floor(T(4)) == T(4)
-     &&  std::bit_floor(T(5)) == T(4)
-     &&  std::bit_floor(T(6)) == T(4)
-     &&  std::bit_floor(T(7)) == T(4)
-     &&  std::bit_floor(T(8)) == T(8)
-     &&  std::bit_floor(T(9)) == T(8)
-     ;
-}
-
-
-template <typename T>
-void runtime_test()
-{
-  ASSERT_SAME_TYPE(T, decltype(std::bit_floor(T(0))));
-  ASSERT_NOEXCEPT(             std::bit_floor(T(0)));
-
-  assert( std::bit_floor(T(121)) == T(64));
-  assert( std::bit_floor(T(122)) == T(64));
-  assert( std::bit_floor(T(123)) == T(64));
-  assert( std::bit_floor(T(124)) == T(64));
-  assert( std::bit_floor(T(125)) == T(64));
-  assert( std::bit_floor(T(126)) == T(64));
-  assert( std::bit_floor(T(127)) == T(64));
-  assert( std::bit_floor(T(128)) == T(128));
-  assert( std::bit_floor(T(129)) == T(128));
-  assert( std::bit_floor(T(130)) == T(128));
-}
-
-int main(int, char**)
-{
+    ASSERT_SAME_TYPE(decltype(std::bit_floor(T())), T);
+    LIBCPP_ASSERT_NOEXCEPT(std::bit_floor(T()));
+    T max = std::numeric_limits<T>::max();
+
+    assert(std::bit_floor(T(0)) == T(0));
+    assert(std::bit_floor(T(1)) == T(1));
+    assert(std::bit_floor(T(2)) == T(2));
+    assert(std::bit_floor(T(3)) == T(2));
+    assert(std::bit_floor(T(4)) == T(4));
+    assert(std::bit_floor(T(5)) == T(4));
+    assert(std::bit_floor(T(6)) == T(4));
+    assert(std::bit_floor(T(7)) == T(4));
+    assert(std::bit_floor(T(8)) == T(8));
+    assert(std::bit_floor(T(9)) == T(8));
+    assert(std::bit_floor(T(125)) == T(64));
+    assert(std::bit_floor(T(126)) == T(64));
+    assert(std::bit_floor(T(127)) == T(64));
+    assert(std::bit_floor(T(128)) == T(128));
+    assert(std::bit_floor(T(129)) == T(128));
+    assert(std::bit_floor(max) == T(max - (max >> 1)));
 
-    {
-    auto lambda = [](auto x) -> decltype(std::bit_floor(x)) {};
-    using L = decltype(lambda);
-
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
-#ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
-#endif
-
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    return true;
 
-  static_assert(constexpr_test<unsigned char>(),      "");
-  static_assert(constexpr_test<unsigned short>(),     "");
-  static_assert(constexpr_test<unsigned>(),           "");
-  static_assert(constexpr_test<unsigned long>(),      "");
-  static_assert(constexpr_test<unsigned long long>(), "");
-
-  static_assert(constexpr_test<uint8_t>(),   "");
-  static_assert(constexpr_test<uint16_t>(),  "");
-  static_assert(constexpr_test<uint32_t>(),  "");
-  static_assert(constexpr_test<uint64_t>(),  "");
-  static_assert(constexpr_test<size_t>(),    "");
-  static_assert(constexpr_test<uintmax_t>(), "");
-  static_assert(constexpr_test<uintptr_t>(), "");
-
-#ifndef _LIBCPP_HAS_NO_INT128
-  static_assert(constexpr_test<__uint128_t>(),        "");
-#endif
-
-  runtime_test<unsigned char>();
-  runtime_test<unsigned>();
-  runtime_test<unsigned short>();
-  runtime_test<unsigned long>();
-  runtime_test<unsigned long long>();
-
-  runtime_test<uint8_t>();
-  runtime_test<uint16_t>();
-  runtime_test<uint32_t>();
-  runtime_test<uint64_t>();
-  runtime_test<size_t>();
-  runtime_test<uintmax_t>();
-  runtime_test<uintptr_t>();
-
 #ifndef _LIBCPP_HAS_NO_INT128
-  runtime_test<__uint128_t>();
-
-  {
-  __uint128_t val = 128;
-  val <<= 32;
-  assert( std::bit_floor(val-1) == val/2);
-  assert( std::bit_floor(val)   == val);
-  assert( std::bit_floor(val+1) == val);
-  val <<= 2;
-  assert( std::bit_floor(val-1) == val/2);
-  assert( std::bit_floor(val)   == val);
-  assert( std::bit_floor(val+1) == val);
-  val <<= 3;
-  assert( std::bit_floor(val-1) == val/2);
-  assert( std::bit_floor(val)   == val);
-  assert( std::bit_floor(val+1) == val);
-  }
+constexpr bool test_uint128()
+    __uint128_t val = 128;
+    val <<= 32;
+    assert(std::bit_floor(val-1) == val/2);
+    assert(std::bit_floor(val)   == val);
+    assert(std::bit_floor(val+1) == val);
+    val <<= 2;
+    assert(std::bit_floor(val-1) == val/2);
+    assert(std::bit_floor(val)   == val);
+    assert(std::bit_floor(val+1) == val);
+    val <<= 3;
+    assert(std::bit_floor(val-1) == val/2);
+    assert(std::bit_floor(val)   == val);
+    assert(std::bit_floor(val+1) == val);
+
+    return true;
+}
+#endif
+
+int main(int, char**)
+{
+    {
+    auto lambda = [](auto x) -> decltype(std::bit_floor(x)) {};
+    using L = decltype(lambda);
+
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
+#ifndef _LIBCPP_HAS_NO_INT128
+    static_assert(!std::is_invocable_v<L, __int128_t>);
+#endif
+
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
+
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
+
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
+#ifndef _LIBCPP_HAS_NO_INT128
+    static_assert(test<__uint128_t>());
+#endif
+
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
+#ifndef _LIBCPP_HAS_NO_INT128
+    test<__uint128_t>();
+#endif
+
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
+
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }

libcxx/test/std/numerics/bit/bit.pow.two/bit_width.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr T bit_width(T x) noexcept;
 
-// If x == 0, 0; otherwise one plus the base-2 logarithm of x, with any fractional part discarded.
+// Constraints: T is an unsigned integer type
+// Returns: If x == 0, 0; otherwise one plus the base-2 logarithm of x, with any fractional part discarded.
 
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
 
 #include <bit>
-#include <cstdint>
 #include <cassert>
+#include <cstdint>
+#include <type_traits>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-  return std::bit_width(T(0)) == T(0)
-     &&  std::bit_width(T(1)) == T(1)
-     &&  std::bit_width(T(2)) == T(2)
-     &&  std::bit_width(T(3)) == T(2)
-     &&  std::bit_width(T(4)) == T(3)
-     &&  std::bit_width(T(5)) == T(3)
-     &&  std::bit_width(T(6)) == T(3)
-     &&  std::bit_width(T(7)) == T(3)
-     &&  std::bit_width(T(8)) == T(4)
-     &&  std::bit_width(T(9)) == T(4)
-     ;
-}
-
-
-template <typename T>
-void runtime_test()
-{
-  ASSERT_SAME_TYPE(T, decltype(std::bit_width(T(0))));
-  ASSERT_NOEXCEPT(             std::bit_width(T(0)));
+    ASSERT_SAME_TYPE(decltype(std::bit_width(T())), T);
+    ASSERT_NOEXCEPT(std::bit_width(T()));
+    T max = std::numeric_limits<T>::max();
 
-  assert( std::bit_width(T(0)) == T(0));
-  assert( std::bit_width(T(1)) == T(1));
-  assert( std::bit_width(T(2)) == T(2));
-  assert( std::bit_width(T(3)) == T(2));
-  assert( std::bit_width(T(4)) == T(3));
-  assert( std::bit_width(T(5)) == T(3));
-  assert( std::bit_width(T(6)) == T(3));
-  assert( std::bit_width(T(7)) == T(3));
-  assert( std::bit_width(T(8)) == T(4));
-  assert( std::bit_width(T(9)) == T(4));
-
-
-  assert( std::bit_width(T(121)) == T(7));
-  assert( std::bit_width(T(122)) == T(7));
-  assert( std::bit_width(T(123)) == T(7));
-  assert( std::bit_width(T(124)) == T(7));
-  assert( std::bit_width(T(125)) == T(7));
-  assert( std::bit_width(T(126)) == T(7));
-  assert( std::bit_width(T(127)) == T(7));
-  assert( std::bit_width(T(128)) == T(8));
-  assert( std::bit_width(T(129)) == T(8));
-  assert( std::bit_width(T(130)) == T(8));
-}
-
-int main(int, char**)
-{
+    assert(std::bit_width(T(0)) == T(0));
+    assert(std::bit_width(T(1)) == T(1));
+    assert(std::bit_width(T(2)) == T(2));
+    assert(std::bit_width(T(3)) == T(2));
+    assert(std::bit_width(T(4)) == T(3));
+    assert(std::bit_width(T(5)) == T(3));
+    assert(std::bit_width(T(6)) == T(3));
+    assert(std::bit_width(T(7)) == T(3));
+    assert(std::bit_width(T(8)) == T(4));
+    assert(std::bit_width(T(9)) == T(4));
+    assert(std::bit_width(T(125)) == T(7));
+    assert(std::bit_width(T(126)) == T(7));
+    assert(std::bit_width(T(127)) == T(7));
+    assert(std::bit_width(T(128)) == T(8));
+    assert(std::bit_width(T(129)) == T(8));
+    assert(std::bit_width(T(130)) == T(8));
+    assert(std::bit_width(T(max - 1)) == T(std::numeric_limits<T>::digits));
+    assert(std::bit_width(max) == T(std::numeric_limits<T>::digits));
 
-    {
-    auto lambda = [](auto x) -> decltype(std::bit_width(x)) {};
-    using L = decltype(lambda);
-
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
-#ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
-#endif
-
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    return true;
 
-  static_assert(constexpr_test<unsigned char>(),      "");
-  static_assert(constexpr_test<unsigned short>(),     "");
-  static_assert(constexpr_test<unsigned>(),           "");
-  static_assert(constexpr_test<unsigned long>(),      "");
-  static_assert(constexpr_test<unsigned long long>(), "");
-
-  static_assert(constexpr_test<uint8_t>(),   "");
-  static_assert(constexpr_test<uint16_t>(),  "");
-  static_assert(constexpr_test<uint32_t>(),  "");
-  static_assert(constexpr_test<uint64_t>(),  "");
-  static_assert(constexpr_test<size_t>(),    "");
-  static_assert(constexpr_test<uintmax_t>(), "");
-  static_assert(constexpr_test<uintptr_t>(), "");
-
-#ifndef _LIBCPP_HAS_NO_INT128
-  static_assert(constexpr_test<__uint128_t>(),        "");
-#endif
-
-
-  runtime_test<unsigned char>();
-  runtime_test<unsigned>();
-  runtime_test<unsigned short>();
-  runtime_test<unsigned long>();
-  runtime_test<unsigned long long>();
-
-  runtime_test<uint8_t>();
-  runtime_test<uint16_t>();
-  runtime_test<uint32_t>();
-  runtime_test<uint64_t>();
-  runtime_test<size_t>();
-  runtime_test<uintmax_t>();
-  runtime_test<uintptr_t>();
-
 #ifndef _LIBCPP_HAS_NO_INT128
-  runtime_test<__uint128_t>();
-
-  {
-  __uint128_t val = 128;
-  val <<= 32;
-  assert( std::bit_width(val-1) == 39);
-  assert( std::bit_width(val)   == 40);
-  assert( std::bit_width(val+1) == 40);
-  val <<= 2;
-  assert( std::bit_width(val-1) == 41);
-  assert( std::bit_width(val)   == 42);
-  assert( std::bit_width(val+1) == 42);
-  val <<= 3;
-  assert( std::bit_width(val-1) == 44);
-  assert( std::bit_width(val)   == 45);
-  assert( std::bit_width(val+1) == 45);
-  }
+constexpr bool test_uint128()
+    __uint128_t val = 128;
+    val <<= 32;
+    assert(std::bit_width(val-1) == 39);
+    assert(std::bit_width(val)   == 40);
+    assert(std::bit_width(val+1) == 40);
+    val <<= 2;
+    assert(std::bit_width(val-1) == 41);
+    assert(std::bit_width(val)   == 42);
+    assert(std::bit_width(val+1) == 42);
+    val <<= 3;
+    assert(std::bit_width(val-1) == 44);
+    assert(std::bit_width(val)   == 45);
+    assert(std::bit_width(val+1) == 45);
+
+    return true;
 #endif
 
+int main(int, char**)
+{
+
+    {
+    auto lambda = [](auto x) -> decltype(std::bit_width(x)) {};
+    using L = decltype(lambda);
+
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
+#ifndef _LIBCPP_HAS_NO_INT128
+    static_assert(!std::is_invocable_v<L, __int128_t>);
+#endif
+
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
+
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
+
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
+#ifndef _LIBCPP_HAS_NO_INT128
+    static_assert(test<__uint128_t>());
+#endif
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
+#ifndef _LIBCPP_HAS_NO_INT128
+    test<__uint128_t>();
+#endif
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
+
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
+#endif
+
     return 0;
 }

libcxx/test/std/numerics/bit/bit.pow.two/has_single_bit.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr bool has_single_bit(T x) noexcept;
 
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
+// Constraints: T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-  return  std::has_single_bit(T(1))
-     &&   std::has_single_bit(T(2))
-     &&  !std::has_single_bit(T(3))
-     &&   std::has_single_bit(T(4))
-     &&  !std::has_single_bit(T(5))
-     &&  !std::has_single_bit(T(6))
-     &&  !std::has_single_bit(T(7))
-     &&   std::has_single_bit(T(8))
-     &&  !std::has_single_bit(T(9))
-     ;
+    ASSERT_SAME_TYPE(decltype(std::has_single_bit(T())), bool);
+    ASSERT_NOEXCEPT(std::has_single_bit(T()));
+    T max = std::numeric_limits<T>::max();
+
+    assert(!std::has_single_bit(T(0)));
+    assert( std::has_single_bit(T(1)));
+    assert( std::has_single_bit(T(2)));
+    assert(!std::has_single_bit(T(3)));
+    assert( std::has_single_bit(T(4)));
+    assert(!std::has_single_bit(T(5)));
+    assert(!std::has_single_bit(T(6)));
+    assert(!std::has_single_bit(T(7)));
+    assert( std::has_single_bit(T(8)));
+    assert(!std::has_single_bit(T(9)));
+    assert(!std::has_single_bit(T(127)));
+    assert( std::has_single_bit(T(128)));
+    assert(!std::has_single_bit(T(129)));
+    assert(!std::has_single_bit(max));
+
+    return true;
 }
 
 
-template <typename T>
-void runtime_test()
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
-  ASSERT_SAME_TYPE(bool, decltype(std::has_single_bit(T(0))));
-  ASSERT_NOEXCEPT(                std::has_single_bit(T(0)));
+    __uint128_t val = 1;
+    val <<= 32;
+    assert(!std::has_single_bit(val-1));
+    assert( std::has_single_bit(val));
+    assert(!std::has_single_bit(val+1));
+    val <<= 32;
+    assert(!std::has_single_bit(val-1));
+    assert( std::has_single_bit(val));
+    assert(!std::has_single_bit(val+1));
+    val <<= 16;
+    assert(!std::has_single_bit(val-1));
+    assert( std::has_single_bit(val));
+    assert(!std::has_single_bit(val+1));
 
-  assert(!std::has_single_bit(T(121)));
-  assert(!std::has_single_bit(T(122)));
-  assert(!std::has_single_bit(T(123)));
-  assert(!std::has_single_bit(T(124)));
-  assert(!std::has_single_bit(T(125)));
-  assert(!std::has_single_bit(T(126)));
-  assert(!std::has_single_bit(T(127)));
-  assert( std::has_single_bit(T(128)));
-  assert(!std::has_single_bit(T(129)));
-  assert(!std::has_single_bit(T(130)));
+    return true;
 }
+#endif
 
 int main(int, char**)
 {
-
     {
     auto lambda = [](auto x) -> decltype(std::has_single_bit(x)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-  static_assert(constexpr_test<unsigned char>(),      "");
-  static_assert(constexpr_test<unsigned short>(),     "");
-  static_assert(constexpr_test<unsigned>(),           "");
-  static_assert(constexpr_test<unsigned long>(),      "");
-  static_assert(constexpr_test<unsigned long long>(), "");
-
-  static_assert(constexpr_test<uint8_t>(),   "");
-  static_assert(constexpr_test<uint16_t>(),  "");
-  static_assert(constexpr_test<uint32_t>(),  "");
-  static_assert(constexpr_test<uint64_t>(),  "");
-  static_assert(constexpr_test<size_t>(),    "");
-  static_assert(constexpr_test<uintmax_t>(), "");
-  static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-  static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
-
-  runtime_test<unsigned char>();
-  runtime_test<unsigned>();
-  runtime_test<unsigned short>();
-  runtime_test<unsigned long>();
-  runtime_test<unsigned long long>();
-
-  runtime_test<uint8_t>();
-  runtime_test<uint16_t>();
-  runtime_test<uint32_t>();
-  runtime_test<uint64_t>();
-  runtime_test<size_t>();
-  runtime_test<uintmax_t>();
-  runtime_test<uintptr_t>();
-
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
 #ifndef _LIBCPP_HAS_NO_INT128
-  runtime_test<__uint128_t>();
+    test<__uint128_t>();
+#endif
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
-  {
-  __uint128_t val = 128;
-  val <<= 32;
-  assert(!std::has_single_bit(val-1));
-  assert( std::has_single_bit(val));
-  assert(!std::has_single_bit(val+1));
-  val <<= 2;
-  assert(!std::has_single_bit(val-1));
-  assert( std::has_single_bit(val));
-  assert(!std::has_single_bit(val+1));
-  val <<= 3;
-  assert(!std::has_single_bit(val-1));
-  assert( std::has_single_bit(val));
-  assert(!std::has_single_bit(val+1));
-  }
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }

libcxx/test/std/numerics/bit/bitops.count/countl_one.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr int countl_one(T x) noexcept;
 
+// Constraints: T is an unsigned integer type
 // The number of consecutive 1 bits, starting from the most significant bit.
 //   [ Note: Returns N if x == std::numeric_limits<T>::max(). ]
-//
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-  const int dig = std::numeric_limits<T>::digits;
-  const T max   = std::numeric_limits<T>::max();
-  return std::countl_one(max) == dig
-     &&  std::countl_one(T(max - 1)) == dig - 1
-     &&  std::countl_one(T(max - 2)) == dig - 2
-     &&  std::countl_one(T(max - 3)) == dig - 2
-     &&  std::countl_one(T(max - 4)) == dig - 3
-     &&  std::countl_one(T(max - 5)) == dig - 3
-     &&  std::countl_one(T(max - 6)) == dig - 3
-     &&  std::countl_one(T(max - 7)) == dig - 3
-     &&  std::countl_one(T(max - 8)) == dig - 4
-     &&  std::countl_one(T(max - 9)) == dig - 4
-    ;
-}
+    ASSERT_SAME_TYPE(decltype(std::countl_one(T())), int);
+    ASSERT_NOEXCEPT(std::countl_one(T()));
+    T max = std::numeric_limits<T>::max();
+
+    assert(std::countl_one(T(0)) == 0);
+    assert(std::countl_one(T(1)) == 0);
+    assert(std::countl_one(T(10)) == 0);
+    assert(std::countl_one(T(100)) == 0);
+    assert(std::countl_one(max) == std::numeric_limits<T>::digits);
+    assert(std::countl_one(T(max - 1)) == std::numeric_limits<T>::digits - 1);
+    assert(std::countl_one(T(max - 2)) == std::numeric_limits<T>::digits - 2);
+    assert(std::countl_one(T(max - 3)) == std::numeric_limits<T>::digits - 2);
+    assert(std::countl_one(T(max - 4)) == std::numeric_limits<T>::digits - 3);
+    assert(std::countl_one(T(max - 5)) == std::numeric_limits<T>::digits - 3);
+    assert(std::countl_one(T(max - 6)) == std::numeric_limits<T>::digits - 3);
+    assert(std::countl_one(T(max - 7)) == std::numeric_limits<T>::digits - 3);
+    assert(std::countl_one(T(max - 8)) == std::numeric_limits<T>::digits - 4);
+    assert(std::countl_one(T(max - 9)) == std::numeric_limits<T>::digits - 4);
+    assert(std::countl_one(T(max - 126)) == std::numeric_limits<T>::digits - 7);
+    assert(std::countl_one(T(max - 127)) == std::numeric_limits<T>::digits - 7);
+    assert(std::countl_one(T(max - 128)) == std::numeric_limits<T>::digits - 8);
 
+    return true;
+}
 
-template <typename T>
-void runtime_test()
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
-  ASSERT_SAME_TYPE(int, decltype(std::countl_one(T(0))));
-  ASSERT_NOEXCEPT(               std::countl_one(T(0)));
-  const int dig = std::numeric_limits<T>::digits;
-
-  assert( std::countl_one(T(~121)) == dig - 7);
-  assert( std::countl_one(T(~122)) == dig - 7);
-  assert( std::countl_one(T(~123)) == dig - 7);
-  assert( std::countl_one(T(~124)) == dig - 7);
-  assert( std::countl_one(T(~125)) == dig - 7);
-  assert( std::countl_one(T(~126)) == dig - 7);
-  assert( std::countl_one(T(~127)) == dig - 7);
-  assert( std::countl_one(T(~128)) == dig - 8);
-  assert( std::countl_one(T(~129)) == dig - 8);
-  assert( std::countl_one(T(~130)) == dig - 8);
+    __uint128_t val = 128;
+    assert(std::countl_one(~val) == 120);
+    val <<= 32;
+    assert(std::countl_one(~val) == 88);
+    val <<= 60;
+    assert(std::countl_one(~val) == 28);
+
+    return true;
 }
+#endif
 
 int main(int, char**)
 {
-  {
+    {
     auto lambda = [](auto x) -> decltype(std::countl_one(x)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-  static_assert(constexpr_test<unsigned char>(),      "");
-  static_assert(constexpr_test<unsigned short>(),     "");
-  static_assert(constexpr_test<unsigned>(),           "");
-  static_assert(constexpr_test<unsigned long>(),      "");
-  static_assert(constexpr_test<unsigned long long>(), "");
-
-  static_assert(constexpr_test<uint8_t>(),   "");
-  static_assert(constexpr_test<uint16_t>(),  "");
-  static_assert(constexpr_test<uint32_t>(),  "");
-  static_assert(constexpr_test<uint64_t>(),  "");
-  static_assert(constexpr_test<size_t>(),    "");
-  static_assert(constexpr_test<uintmax_t>(), "");
-  static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-  static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
-
-
-  runtime_test<unsigned char>();
-  runtime_test<unsigned>();
-  runtime_test<unsigned short>();
-  runtime_test<unsigned long>();
-  runtime_test<unsigned long long>();
-
-  runtime_test<uint8_t>();
-  runtime_test<uint16_t>();
-  runtime_test<uint32_t>();
-  runtime_test<uint64_t>();
-  runtime_test<size_t>();
-  runtime_test<uintmax_t>();
-  runtime_test<uintptr_t>();
-
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
 #ifndef _LIBCPP_HAS_NO_INT128
-  runtime_test<__uint128_t>();
-
-  {
-  const int dig = std::numeric_limits<__uint128_t>::digits;
-  __uint128_t val = 128;
+    test<__uint128_t>();
+#endif
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
-  val <<= 32;
-  assert( std::countl_one(~val)   == dig - 40);
-  val <<= 2;
-  assert( std::countl_one(~val)   == dig - 42);
-  val <<= 3;
-  assert( std::countl_one(~val)   == dig - 45);
-  }
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }
+

libcxx/test/std/numerics/bit/bitops.count/countl_zero.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr int countl_zero(T x) noexcept;
 
+// Constraints: T is an unsigned integer type
 // Returns: The number of consecutive 0 bits, starting from the most significant bit.
 //   [ Note: Returns N if x == 0. ]
-//
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-  const int dig = std::numeric_limits<T>::digits;
-  return std::countl_zero(T(0)) == dig
-     &&  std::countl_zero(T(1)) == dig - 1
-     &&  std::countl_zero(T(2)) == dig - 2
-     &&  std::countl_zero(T(3)) == dig - 2
-     &&  std::countl_zero(T(4)) == dig - 3
-     &&  std::countl_zero(T(5)) == dig - 3
-     &&  std::countl_zero(T(6)) == dig - 3
-     &&  std::countl_zero(T(7)) == dig - 3
-     &&  std::countl_zero(T(8)) == dig - 4
-     &&  std::countl_zero(T(9)) == dig - 4
-     &&  std::countl_zero(std::numeric_limits<T>::max()) == 0
-    ;
-}
+    ASSERT_SAME_TYPE(decltype(std::countl_zero(T())), int);
+    ASSERT_NOEXCEPT(std::countl_zero(T()));
+    T max = std::numeric_limits<T>::max();
+    int dig = std::numeric_limits<T>::digits;
+
+    assert(std::countl_zero(T(0)) == dig);
+    assert(std::countl_zero(T(1)) == dig - 1);
+    assert(std::countl_zero(T(2)) == dig - 2);
+    assert(std::countl_zero(T(3)) == dig - 2);
+    assert(std::countl_zero(T(4)) == dig - 3);
+    assert(std::countl_zero(T(5)) == dig - 3);
+    assert(std::countl_zero(T(6)) == dig - 3);
+    assert(std::countl_zero(T(7)) == dig - 3);
+    assert(std::countl_zero(T(8)) == dig - 4);
+    assert(std::countl_zero(T(9)) == dig - 4);
+    assert(std::countl_zero(T(127)) == dig - 7);
+    assert(std::countl_zero(T(128)) == dig - 8);
+    assert(std::countl_zero(max) == 0);
 
+    return true;
+}
 
-template <typename T>
-void runtime_test()
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
-  ASSERT_SAME_TYPE(int, decltype(std::countl_zero(T(0))));
-  ASSERT_NOEXCEPT(               std::countl_zero(T(0)));
-  const int dig = std::numeric_limits<T>::digits;
-
-  assert( std::countl_zero(T(121)) == dig - 7);
-  assert( std::countl_zero(T(122)) == dig - 7);
-  assert( std::countl_zero(T(123)) == dig - 7);
-  assert( std::countl_zero(T(124)) == dig - 7);
-  assert( std::countl_zero(T(125)) == dig - 7);
-  assert( std::countl_zero(T(126)) == dig - 7);
-  assert( std::countl_zero(T(127)) == dig - 7);
-  assert( std::countl_zero(T(128)) == dig - 8);
-  assert( std::countl_zero(T(129)) == dig - 8);
-  assert( std::countl_zero(T(130)) == dig - 8);
+    __uint128_t val = 128;
+    val <<= 32;
+    assert(std::countl_zero(val-1) == 128 - 39);
+    assert(std::countl_zero(val)   == 128 - 40);
+    assert(std::countl_zero(val+1) == 128 - 40);
+    val <<= 60;
+    assert(std::countl_zero(val-1) == 128 - 99);
+    assert(std::countl_zero(val)   == 128 - 100);
+    assert(std::countl_zero(val+1) == 128 - 100);
+
+    return true;
 }
+#endif
 
 int main(int, char**)
 {
-
     {
     auto lambda = [](auto x) -> decltype(std::countl_zero(x)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-  static_assert(constexpr_test<unsigned char>(),      "");
-  static_assert(constexpr_test<unsigned short>(),     "");
-  static_assert(constexpr_test<unsigned>(),           "");
-  static_assert(constexpr_test<unsigned long>(),      "");
-  static_assert(constexpr_test<unsigned long long>(), "");
-
-  static_assert(constexpr_test<uint8_t>(),   "");
-  static_assert(constexpr_test<uint16_t>(),  "");
-  static_assert(constexpr_test<uint32_t>(),  "");
-  static_assert(constexpr_test<uint64_t>(),  "");
-  static_assert(constexpr_test<size_t>(),    "");
-  static_assert(constexpr_test<uintmax_t>(), "");
-  static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-  static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
-
-
-  runtime_test<unsigned char>();
-  runtime_test<unsigned>();
-  runtime_test<unsigned short>();
-  runtime_test<unsigned long>();
-  runtime_test<unsigned long long>();
-
-  runtime_test<uint8_t>();
-  runtime_test<uint16_t>();
-  runtime_test<uint32_t>();
-  runtime_test<uint64_t>();
-  runtime_test<size_t>();
-  runtime_test<uintmax_t>();
-  runtime_test<uintptr_t>();
-
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
 #ifndef _LIBCPP_HAS_NO_INT128
-  runtime_test<__uint128_t>();
-
-  {
-  const int dig = std::numeric_limits<__uint128_t>::digits;
-  __uint128_t val = 128;
+    test<__uint128_t>();
+#endif
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
-  val <<= 32;
-  assert( std::countl_zero(val-1) == dig - 39);
-  assert( std::countl_zero(val)   == dig - 40);
-  assert( std::countl_zero(val+1) == dig - 40);
-  val <<= 2;
-  assert( std::countl_zero(val-1) == dig - 41);
-  assert( std::countl_zero(val)   == dig - 42);
-  assert( std::countl_zero(val+1) == dig - 42);
-  val <<= 3;
-  assert( std::countl_zero(val-1) == dig - 44);
-  assert( std::countl_zero(val)   == dig - 45);
-  assert( std::countl_zero(val+1) == dig - 45);
-  }
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }

libcxx/test/std/numerics/bit/bitops.count/countr_one.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr int countr_one(T x) noexcept;
 
+// Constraints: T is an unsigned integer type
 // Returns: The number of consecutive 1 bits, starting from the least significant bit.
 //   [ Note: Returns N if x == std::numeric_limits<T>::max(). ]
-//
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
 
 #include <bit>
 #include <cstdint>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-  const int dig = std::numeric_limits<T>::digits;
-  return std::countr_one(T(0)) == 0
-     &&  std::countr_one(T(1)) == 1
-     &&  std::countr_one(T(2)) == 0
-     &&  std::countr_one(T(3)) == 2
-     &&  std::countr_one(T(4)) == 0
-     &&  std::countr_one(T(5)) == 1
-     &&  std::countr_one(T(6)) == 0
-     &&  std::countr_one(T(7)) == 3
-     &&  std::countr_one(T(8)) == 0
-     &&  std::countr_one(T(9)) == 1
-     &&  std::countr_one(std::numeric_limits<T>::max()) == dig
-    ;
-}
+    ASSERT_SAME_TYPE(decltype(std::countr_one(T())), int);
+    ASSERT_NOEXCEPT(std::countr_one(T()));
+    T max = std::numeric_limits<T>::max();
+
+    assert(std::countr_one(T(0)) == 0);
+    assert(std::countr_one(T(1)) == 1);
+    assert(std::countr_one(T(2)) == 0);
+    assert(std::countr_one(T(3)) == 2);
+    assert(std::countr_one(T(4)) == 0);
+    assert(std::countr_one(T(5)) == 1);
+    assert(std::countr_one(T(6)) == 0);
+    assert(std::countr_one(T(7)) == 3);
+    assert(std::countr_one(T(8)) == 0);
+    assert(std::countr_one(T(9)) == 1);
+    assert(std::countr_one(T(126)) == 0);
+    assert(std::countr_one(T(127)) == 7);
+    assert(std::countr_one(T(128)) == 0);
+    assert(std::countr_one(T(max - 1)) == 0);
+    assert(std::countr_one(max) == std::numeric_limits<T>::digits);
 
+    return true;
+}
 
-template <typename T>
-void runtime_test()
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
-  ASSERT_SAME_TYPE(int, decltype(std::countr_one(T(0))));
-  ASSERT_NOEXCEPT(               std::countr_one(T(0)));
+    __uint128_t val = 128;
+    assert(std::countr_one(val-1) ==  7);
+    assert(std::countr_one(val)   ==  0);
+    assert(std::countr_one(val+1) ==  1);
+    val <<= 32;
+    assert(std::countr_one(val-1) == 39);
+    assert(std::countr_one(val)   ==  0);
+    assert(std::countr_one(val+1) ==  1);
+    val <<= 60;
+    assert(std::countr_one(val-1) == 99);
+    assert(std::countr_one(val)   ==  0);
+    assert(std::countr_one(val+1) ==  1);
 
-  assert( std::countr_one(T(121)) == 1);
-  assert( std::countr_one(T(122)) == 0);
-  assert( std::countr_one(T(123)) == 2);
-  assert( std::countr_one(T(124)) == 0);
-  assert( std::countr_one(T(125)) == 1);
-  assert( std::countr_one(T(126)) == 0);
-  assert( std::countr_one(T(127)) == 7);
-  assert( std::countr_one(T(128)) == 0);
-  assert( std::countr_one(T(129)) == 1);
-  assert( std::countr_one(T(130)) == 0);
+    return true;
 }
+#endif
 
 int main(int, char**)
 {
-
     {
     auto lambda = [](auto x) -> decltype(std::countr_one(x)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-  static_assert(constexpr_test<unsigned char>(),      "");
-  static_assert(constexpr_test<unsigned short>(),     "");
-  static_assert(constexpr_test<unsigned>(),           "");
-  static_assert(constexpr_test<unsigned long>(),      "");
-  static_assert(constexpr_test<unsigned long long>(), "");
-
-  static_assert(constexpr_test<uint8_t>(),   "");
-  static_assert(constexpr_test<uint16_t>(),  "");
-  static_assert(constexpr_test<uint32_t>(),  "");
-  static_assert(constexpr_test<uint64_t>(),  "");
-  static_assert(constexpr_test<size_t>(),    "");
-  static_assert(constexpr_test<uintmax_t>(), "");
-  static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-  static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
-
-
-  runtime_test<unsigned char>();
-  runtime_test<unsigned>();
-  runtime_test<unsigned short>();
-  runtime_test<unsigned long>();
-  runtime_test<unsigned long long>();
-
-  runtime_test<uint8_t>();
-  runtime_test<uint16_t>();
-  runtime_test<uint32_t>();
-  runtime_test<uint64_t>();
-  runtime_test<size_t>();
-  runtime_test<uintmax_t>();
-  runtime_test<uintptr_t>();
-
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
 #ifndef _LIBCPP_HAS_NO_INT128
-  runtime_test<__uint128_t>();
-
-  {
-  __uint128_t val = 128;
+    test<__uint128_t>();
+#endif
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
-  val <<= 32;
-  assert( std::countr_one(val-1) == 39);
-  assert( std::countr_one(val)   ==  0);
-  assert( std::countr_one(val+1) ==  1);
-  val <<= 2;
-  assert( std::countr_one(val-1) == 41);
-  assert( std::countr_one(val)   ==  0);
-  assert( std::countr_one(val+1) ==  1);
-  val <<= 3;
-  assert( std::countr_one(val-1) == 44);
-  assert( std::countr_one(val)   ==  0);
-  assert( std::countr_one(val+1) ==  1);
-  }
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }

libcxx/test/std/numerics/bit/bitops.count/countr_zero.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr int countr_zero(T x) noexcept;
 
+// Constraints: T is an unsigned integer type
 // Returns: The number of consecutive 0 bits, starting from the most significant bit.
 //   [ Note: Returns N if x == 0. ]
-//
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-  const int dig = std::numeric_limits<T>::digits;
-  return std::countr_zero(T(0)) == dig
-     &&  std::countr_zero(T(1)) == 0
-     &&  std::countr_zero(T(2)) == 1
-     &&  std::countr_zero(T(3)) == 0
-     &&  std::countr_zero(T(4)) == 2
-     &&  std::countr_zero(T(5)) == 0
-     &&  std::countr_zero(T(6)) == 1
-     &&  std::countr_zero(T(7)) == 0
-     &&  std::countr_zero(T(8)) == 3
-     &&  std::countr_zero(T(9)) == 0
-     &&  std::countr_zero(std::numeric_limits<T>::max()) == 0
-    ;
-}
-
-
-template <typename T>
-void runtime_test()
-{
-  ASSERT_SAME_TYPE(int, decltype(std::countr_zero(T(0))));
-  ASSERT_NOEXCEPT(               std::countr_zero(T(0)));
-
-  assert( std::countr_zero(T(121)) == 0);
-  assert( std::countr_zero(T(122)) == 1);
-  assert( std::countr_zero(T(123)) == 0);
-  assert( std::countr_zero(T(124)) == 2);
-  assert( std::countr_zero(T(125)) == 0);
-  assert( std::countr_zero(T(126)) == 1);
-  assert( std::countr_zero(T(127)) == 0);
-  assert( std::countr_zero(T(128)) == 7);
-  assert( std::countr_zero(T(129)) == 0);
-  assert( std::countr_zero(T(130)) == 1);
+    ASSERT_SAME_TYPE(decltype(std::countr_zero(T())), int);
+    ASSERT_NOEXCEPT(std::countr_zero(T()));
+    T max = std::numeric_limits<T>::max();
+
+    assert(std::countr_zero(T(0)) == std::numeric_limits<T>::digits);
+    assert(std::countr_zero(T(1)) == 0);
+    assert(std::countr_zero(T(2)) == 1);
+    assert(std::countr_zero(T(3)) == 0);
+    assert(std::countr_zero(T(4)) == 2);
+    assert(std::countr_zero(T(5)) == 0);
+    assert(std::countr_zero(T(6)) == 1);
+    assert(std::countr_zero(T(7)) == 0);
+    assert(std::countr_zero(T(8)) == 3);
+    assert(std::countr_zero(T(9)) == 0);
+    assert(std::countr_zero(T(126)) == 1);
+    assert(std::countr_zero(T(127)) == 0);
+    assert(std::countr_zero(T(128)) == 7);
+    assert(std::countr_zero(T(129)) == 0);
+    assert(std::countr_zero(T(130)) == 1);
+    assert(std::countr_zero(max) == 0);
+
+    return true;
 }
 
-int main(int, char**)
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
+    __uint128_t val = 128;
+    val <<= 32;
+    assert(std::countr_zero(val-1) ==  0);
+    assert(std::countr_zero(val)   == 39);
+    assert(std::countr_zero(val+1) ==  0);
+    val <<= 60;
+    assert(std::countr_zero(val-1) ==  0);
+    assert(std::countr_zero(val)   == 99);
+    assert(std::countr_zero(val+1) ==  0);
 
+    return true;
+}
+#endif
+
+int main(int, char**)
+{
     {
     auto lambda = [](auto x) -> decltype(std::countr_zero(x)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-  static_assert(constexpr_test<unsigned char>(),      "");
-  static_assert(constexpr_test<unsigned short>(),     "");
-  static_assert(constexpr_test<unsigned>(),           "");
-  static_assert(constexpr_test<unsigned long>(),      "");
-  static_assert(constexpr_test<unsigned long long>(), "");
-
-  static_assert(constexpr_test<uint8_t>(),   "");
-  static_assert(constexpr_test<uint16_t>(),  "");
-  static_assert(constexpr_test<uint32_t>(),  "");
-  static_assert(constexpr_test<uint64_t>(),  "");
-  static_assert(constexpr_test<size_t>(),    "");
-  static_assert(constexpr_test<uintmax_t>(), "");
-  static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-  static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
-
-  runtime_test<unsigned char>();
-  runtime_test<unsigned>();
-  runtime_test<unsigned short>();
-  runtime_test<unsigned long>();
-  runtime_test<unsigned long long>();
-
-  runtime_test<uint8_t>();
-  runtime_test<uint16_t>();
-  runtime_test<uint32_t>();
-  runtime_test<uint64_t>();
-  runtime_test<size_t>();
-  runtime_test<uintmax_t>();
-  runtime_test<uintptr_t>();
-
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
 #ifndef _LIBCPP_HAS_NO_INT128
-  runtime_test<__uint128_t>();
-
-  {
-  __uint128_t val = 128;
+    test<__uint128_t>();
+#endif
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
-  val <<= 32;
-  assert( std::countr_zero(val-1) ==  0);
-  assert( std::countr_zero(val)   == 39);
-  assert( std::countr_zero(val+1) ==  0);
-  val <<= 2;
-  assert( std::countr_zero(val-1) ==  0);
-  assert( std::countr_zero(val)   == 41);
-  assert( std::countr_zero(val+1) ==  0);
-  val <<= 3;
-  assert( std::countr_zero(val-1) ==  0);
-  assert( std::countr_zero(val)   == 44);
-  assert( std::countr_zero(val+1) ==  0);
-  }
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }

libcxx/test/std/numerics/bit/bitops.count/popcount.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr int popcount(T x) noexcept;
 
+// Constraints: T is an unsigned integer type
 // Returns: The number of bits set to one in the value of x.
-//
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
-{
-  return std::popcount(T(0)) == 0
-     &&  std::popcount(T(1)) == 1
-     &&  std::popcount(T(2)) == 1
-     &&  std::popcount(T(3)) == 2
-     &&  std::popcount(T(4)) == 1
-     &&  std::popcount(T(5)) == 2
-     &&  std::popcount(T(6)) == 2
-     &&  std::popcount(T(7)) == 3
-     &&  std::popcount(T(8)) == 1
-     &&  std::popcount(T(9)) == 2
-     &&  std::popcount(std::numeric_limits<T>::max()) == std::numeric_limits<T>::digits
-    ;
-}
-
-
-template <typename T>
-void runtime_test()
+template <class T>
+constexpr bool test()
 {
-  ASSERT_SAME_TYPE(int, decltype(std::popcount(T(0))));
-  ASSERT_NOEXCEPT(               std::popcount(T(0)));
-
-  assert( std::popcount(T(121)) == 5);
-  assert( std::popcount(T(122)) == 5);
-  assert( std::popcount(T(123)) == 6);
-  assert( std::popcount(T(124)) == 5);
-  assert( std::popcount(T(125)) == 6);
-  assert( std::popcount(T(126)) == 6);
-  assert( std::popcount(T(127)) == 7);
-  assert( std::popcount(T(128)) == 1);
-  assert( std::popcount(T(129)) == 2);
-  assert( std::popcount(T(130)) == 2);
+    ASSERT_SAME_TYPE(decltype(std::popcount(T())), int);
+    ASSERT_NOEXCEPT(std::popcount(T()));
+    T max = std::numeric_limits<T>::max();
+
+    assert(std::popcount(T(0)) == 0);
+    assert(std::popcount(T(1)) == 1);
+    assert(std::popcount(T(2)) == 1);
+    assert(std::popcount(T(3)) == 2);
+    assert(std::popcount(T(4)) == 1);
+    assert(std::popcount(T(5)) == 2);
+    assert(std::popcount(T(6)) == 2);
+    assert(std::popcount(T(7)) == 3);
+    assert(std::popcount(T(8)) == 1);
+    assert(std::popcount(T(9)) == 2);
+    assert(std::popcount(T(121)) == 5);
+    assert(std::popcount(T(127)) == 7);
+    assert(std::popcount(T(128)) == 1);
+    assert(std::popcount(T(130)) == 2);
+    assert(std::popcount(T(max >> 1)) == std::numeric_limits<T>::digits - 1);
+    assert(std::popcount(T(max - 1)) == std::numeric_limits<T>::digits - 1);
+    assert(std::popcount(max) == std::numeric_limits<T>::digits);
+
+    return true;
 }
 
-int main(int, char**)
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
+    __uint128_t val = 128;
+    assert(std::popcount(val-1) ==  7);
+    assert(std::popcount(val)   ==  1);
+    assert(std::popcount(val+1) ==  2);
+    val <<= 32;
+    assert(std::popcount(val-1) == 39);
+    assert(std::popcount(val)   ==  1);
+    assert(std::popcount(val+1) ==  2);
+    val <<= 60;
+    assert(std::popcount(val-1) == 99);
+    assert(std::popcount(val)   ==  1);
+    assert(std::popcount(val+1) ==  2);
+
+    return true;
+}
+#endif
 
+int main(int, char**)
+{
     {
     auto lambda = [](auto x) -> decltype(std::popcount(x)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L, __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-  static_assert(constexpr_test<unsigned char>(),      "");
-  static_assert(constexpr_test<unsigned short>(),     "");
-  static_assert(constexpr_test<unsigned>(),           "");
-  static_assert(constexpr_test<unsigned long>(),      "");
-  static_assert(constexpr_test<unsigned long long>(), "");
-
-  static_assert(constexpr_test<uint8_t>(),   "");
-  static_assert(constexpr_test<uint16_t>(),  "");
-  static_assert(constexpr_test<uint32_t>(),  "");
-  static_assert(constexpr_test<uint64_t>(),  "");
-  static_assert(constexpr_test<size_t>(),    "");
-  static_assert(constexpr_test<uintmax_t>(), "");
-  static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-  static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
-
-
-  runtime_test<unsigned char>();
-  runtime_test<unsigned>();
-  runtime_test<unsigned short>();
-  runtime_test<unsigned long>();
-  runtime_test<unsigned long long>();
-
-  runtime_test<uint8_t>();
-  runtime_test<uint16_t>();
-  runtime_test<uint32_t>();
-  runtime_test<uint64_t>();
-  runtime_test<size_t>();
-  runtime_test<uintmax_t>();
-  runtime_test<uintptr_t>();
-
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
 #ifndef _LIBCPP_HAS_NO_INT128
-  runtime_test<__uint128_t>();
-
-  {
-  __uint128_t val = 128;
+    test<__uint128_t>();
+#endif
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
-  val <<= 32;
-  assert( std::popcount(val-1) == 39);
-  assert( std::popcount(val)   ==  1);
-  assert( std::popcount(val+1) ==  2);
-  val <<= 2;
-  assert( std::popcount(val-1) == 41);
-  assert( std::popcount(val)   ==  1);
-  assert( std::popcount(val+1) ==  2);
-  val <<= 3;
-  assert( std::popcount(val-1) == 44);
-  assert( std::popcount(val)   ==  1);
-  assert( std::popcount(val+1) ==  2);
-  }
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }

libcxx/test/std/numerics/bit/bitops.rot/rotl.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr int rotl(T x, unsigned int s) noexcept;
 
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
+// Constraints: T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-    const T max = std::numeric_limits<T>::max();
-    return std::rotl(T(1), 0) == T( 1)
-       &&  std::rotl(T(1), 1) == T( 2)
-       &&  std::rotl(T(1), 2) == T( 4)
-       &&  std::rotl(T(1), 3) == T( 8)
-       &&  std::rotl(T(1), 4) == T( 16)
-       &&  std::rotl(T(1), 5) == T( 32)
-       &&  std::rotl(T(1), 6) == T( 64)
-       &&  std::rotl(T(1), 7) == T(128)
-       &&  std::rotl(max, 0)  == max
-       &&  std::rotl(max, 1)  == max
-       &&  std::rotl(max, 2)  == max
-       &&  std::rotl(max, 3)  == max
-       &&  std::rotl(max, 4)  == max
-       &&  std::rotl(max, 5)  == max
-       &&  std::rotl(max, 6)  == max
-       &&  std::rotl(max, 7)  == max
-      ;
-}
+    ASSERT_SAME_TYPE(decltype(std::rotl(T(), 0)), T);
+    ASSERT_NOEXCEPT(std::rotl(T(), 0));
+    T max = std::numeric_limits<T>::max();
+
+    assert(std::rotl(T(max - 1), 0) == T(max - 1));
+    assert(std::rotl(T(max - 1), 1) == T(max - 2));
+    assert(std::rotl(T(max - 1), 2) == T(max - 4));
+    assert(std::rotl(T(max - 1), 3) == T(max - 8));
+    assert(std::rotl(T(max - 1), 4) == T(max - 16));
+    assert(std::rotl(T(max - 1), 5) == T(max - 32));
+    assert(std::rotl(T(max - 1), 6) == T(max - 64));
+    assert(std::rotl(T(max - 1), 7) == T(max - 128));
+
+    assert(std::rotl(T(1), 0) == T(1));
+    assert(std::rotl(T(1), 1) == T(2));
+    assert(std::rotl(T(1), 2) == T(4));
+    assert(std::rotl(T(1), 3) == T(8));
+    assert(std::rotl(T(1), 4) == T(16));
+    assert(std::rotl(T(1), 5) == T(32));
+    assert(std::rotl(T(1), 6) == T(64));
+    assert(std::rotl(T(1), 7) == T(128));
 
+    return true;
+}
 
-template <typename T>
-void runtime_test()
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
-    ASSERT_SAME_TYPE(T, decltype(std::rotl(T(0), 0)));
-    ASSERT_NOEXCEPT(             std::rotl(T(0), 0));
-    const T val = std::numeric_limits<T>::max() - 1;
-
-    assert( std::rotl(val, 0) == val);
-    assert( std::rotl(val, 1) == T((val << 1) +   1));
-    assert( std::rotl(val, 2) == T((val << 2) +   3));
-    assert( std::rotl(val, 3) == T((val << 3) +   7));
-    assert( std::rotl(val, 4) == T((val << 4) +  15));
-    assert( std::rotl(val, 5) == T((val << 5) +  31));
-    assert( std::rotl(val, 6) == T((val << 6) +  63));
-    assert( std::rotl(val, 7) == T((val << 7) + 127));
+    __uint128_t val = 168; // 0xA8 (aka 10101000)
+
+    assert( std::rotl(val, 128) == 168);
+    val <<= 32;
+    assert( std::rotl(val,  96) == 168);
+    val <<= 2;
+    assert( std::rotl(val,  95) == 336);
+    val <<= 3;
+    assert( std::rotl(val,  90) ==  84);
+    assert( std::rotl(val, 218) ==  84);
+
+    return true;
 }
+#endif
 
 int main(int, char**)
 {
-
     {
     auto lambda = [](auto x) -> decltype(std::rotl(x, 1U)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L,  __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A>, "");
-    static_assert(!std::is_invocable_v<L, E1>, "");
-    static_assert(!std::is_invocable_v<L, E2>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-    static_assert(constexpr_test<unsigned char>(),      "");
-    static_assert(constexpr_test<unsigned short>(),     "");
-    static_assert(constexpr_test<unsigned>(),           "");
-    static_assert(constexpr_test<unsigned long>(),      "");
-    static_assert(constexpr_test<unsigned long long>(), "");
-
-    static_assert(constexpr_test<uint8_t>(),   "");
-    static_assert(constexpr_test<uint16_t>(),  "");
-    static_assert(constexpr_test<uint32_t>(),  "");
-    static_assert(constexpr_test<uint64_t>(),  "");
-    static_assert(constexpr_test<size_t>(),    "");
-    static_assert(constexpr_test<uintmax_t>(), "");
-    static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
 
-
-    runtime_test<unsigned char>();
-    runtime_test<unsigned short>();
-    runtime_test<unsigned>();
-    runtime_test<unsigned long>();
-    runtime_test<unsigned long long>();
-
-    runtime_test<uint8_t>();
-    runtime_test<uint16_t>();
-    runtime_test<uint32_t>();
-    runtime_test<uint64_t>();
-    runtime_test<size_t>();
-    runtime_test<uintmax_t>();
-    runtime_test<uintptr_t>();
-
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
 #ifndef _LIBCPP_HAS_NO_INT128
-    runtime_test<__uint128_t>();
+    test<__uint128_t>();
+#endif
 
-    {
-    __uint128_t val = 168; // 0xA8 (aka 10101000)
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
-    assert( std::rotl(val, 128) == 168);
-    val <<= 32;
-    assert( std::rotl(val,  96) == 168);
-    val <<= 2;
-    assert( std::rotl(val,  95) == 336);
-    val <<= 3;
-    assert( std::rotl(val,  90) ==  84);
-    assert( std::rotl(val, 218) ==  84);
-    }
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }

libcxx/test/std/numerics/bit/bitops.rot/rotr.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // template <class T>
 //   constexpr int rotr(T x, unsigned int s) noexcept;
 
-// Remarks: This function shall not participate in overload resolution unless
-//  T is an unsigned integer type
+// Constraints: T is an unsigned integer type
 
 #include <bit>
+#include <cassert>
 #include <cstdint>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
-class A{};
+struct A {};
 enum       E1 : unsigned char { rEd };
 enum class E2 : unsigned char { red };
 
-template <typename T>
-constexpr bool constexpr_test()
+template <class T>
+constexpr bool test()
 {
-    const T max = std::numeric_limits<T>::max();
+    ASSERT_SAME_TYPE(decltype(std::rotr(T(), 0)), T);
+    ASSERT_NOEXCEPT(std::rotr(T(), 0));
+    T max = std::numeric_limits<T>::max();
+    T highbit = std::rotr(T(1), 1);
+
+    assert(std::rotr(T(max - 1), 0) == T(max - 1));
+    assert(std::rotr(T(max - 1), 1) == T(max - highbit));
+    assert(std::rotr(T(max - 1), 2) == T(max - (highbit >> 1)));
+    assert(std::rotr(T(max - 1), 3) == T(max - (highbit >> 2)));
+    assert(std::rotr(T(max - 1), 4) == T(max - (highbit >> 3)));
+    assert(std::rotr(T(max - 1), 5) == T(max - (highbit >> 4)));
+    assert(std::rotr(T(max - 1), 6) == T(max - (highbit >> 5)));
+    assert(std::rotr(T(max - 1), 7) == T(max - (highbit >> 6)));
+
+    assert(std::rotr(T(128), 0) == T(128));
+    assert(std::rotr(T(128), 1) == T(64));
+    assert(std::rotr(T(128), 2) == T(32));
+    assert(std::rotr(T(128), 3) == T(16));
+    assert(std::rotr(T(128), 4) == T(8));
+    assert(std::rotr(T(128), 5) == T(4));
+    assert(std::rotr(T(128), 6) == T(2));
+    assert(std::rotr(T(128), 7) == T(1));
 
-    return std::rotr(T(128), 0) == T(128)
-       &&  std::rotr(T(128), 1) == T( 64)
-       &&  std::rotr(T(128), 2) == T( 32)
-       &&  std::rotr(T(128), 3) == T( 16)
-       &&  std::rotr(T(128), 4) == T(  8)
-       &&  std::rotr(T(128), 5) == T(  4)
-       &&  std::rotr(T(128), 6) == T(  2)
-       &&  std::rotr(T(128), 7) == T(  1)
-       &&  std::rotr(max, 0)  == max
-       &&  std::rotr(max, 1)  == max
-       &&  std::rotr(max, 2)  == max
-       &&  std::rotr(max, 3)  == max
-       &&  std::rotr(max, 4)  == max
-       &&  std::rotr(max, 5)  == max
-       &&  std::rotr(max, 6)  == max
-       &&  std::rotr(max, 7)  == max
-      ;
+    return true;
 }
 
-
-template <typename T>
-void runtime_test()
+#ifndef _LIBCPP_HAS_NO_INT128
+constexpr bool test_uint128()
 {
-    ASSERT_SAME_TYPE(T, decltype(std::rotr(T(0), 0)));
-    ASSERT_NOEXCEPT(             std::rotr(T(0), 0));
-    const T max = std::numeric_limits<T>::max();
-    const T val = std::numeric_limits<T>::max() - 1;
-
-    const T uppers [] = {
-        max,              // not used
-        max - max,        // 000 .. 0
-        max - (max >> 1), // 800 .. 0
-        max - (max >> 2), // C00 .. 0
-        max - (max >> 3), // E00 .. 0
-        max - (max >> 4), // F00 .. 0
-        max - (max >> 5), // F80 .. 0
-        max - (max >> 6), // FC0 .. 0
-        max - (max >> 7), // FE0 .. 0
-        };
-
-    assert( std::rotr(val, 0) == val);
-    assert( std::rotr(val, 1) == T((val >> 1) +  uppers[1]));
-    assert( std::rotr(val, 2) == T((val >> 2) +  uppers[2]));
-    assert( std::rotr(val, 3) == T((val >> 3) +  uppers[3]));
-    assert( std::rotr(val, 4) == T((val >> 4) +  uppers[4]));
-    assert( std::rotr(val, 5) == T((val >> 5) +  uppers[5]));
-    assert( std::rotr(val, 6) == T((val >> 6) +  uppers[6]));
-    assert( std::rotr(val, 7) == T((val >> 7) +  uppers[7]));
+    __uint128_t val = 168; // 0xA8 (aka 10101000)
+
+    assert( std::rotr(val, 128) == 168);
+    val <<= 32;
+    assert( std::rotr(val,  32) == 168);
+    val <<= 2;
+    assert( std::rotr(val,  33) == 336);
+    val <<= 3;
+    assert( std::rotr(val,  38) ==  84);
+    assert( std::rotr(val, 166) ==  84);
+
+    return true;
 }
+#endif
 
 int main(int, char**)
 {
-
     {
-    auto lambda = [](auto x) -> decltype(std::rotr(x, 1U)) {};
+    auto lambda = [](auto x) -> decltype(std::rotl(x, 1U)) {};
     using L = decltype(lambda);
 
-    static_assert( std::is_invocable_v<L, unsigned char>, "");
-    static_assert( std::is_invocable_v<L, unsigned int>, "");
-    static_assert( std::is_invocable_v<L, unsigned long>, "");
-    static_assert( std::is_invocable_v<L, unsigned long long>, "");
-
-    static_assert( std::is_invocable_v<L, uint8_t>, "");
-    static_assert( std::is_invocable_v<L, uint16_t>, "");
-    static_assert( std::is_invocable_v<L, uint32_t>, "");
-    static_assert( std::is_invocable_v<L, uint64_t>, "");
-    static_assert( std::is_invocable_v<L, size_t>, "");
-
-    static_assert( std::is_invocable_v<L, uintmax_t>, "");
-    static_assert( std::is_invocable_v<L, uintptr_t>, "");
-
-
-    static_assert(!std::is_invocable_v<L, int>, "");
-    static_assert(!std::is_invocable_v<L, signed int>, "");
-    static_assert(!std::is_invocable_v<L, long>, "");
-    static_assert(!std::is_invocable_v<L, long long>, "");
-
-    static_assert(!std::is_invocable_v<L, int8_t>, "");
-    static_assert(!std::is_invocable_v<L, int16_t>, "");
-    static_assert(!std::is_invocable_v<L, int32_t>, "");
-    static_assert(!std::is_invocable_v<L, int64_t>, "");
-    static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
-
-    static_assert(!std::is_invocable_v<L, bool>, "");
-    static_assert(!std::is_invocable_v<L, signed char>, "");
-    static_assert(!std::is_invocable_v<L, char16_t>, "");
-    static_assert(!std::is_invocable_v<L, char32_t>, "");
-
+    static_assert(!std::is_invocable_v<L, signed char>);
+    static_assert(!std::is_invocable_v<L, short>);
+    static_assert(!std::is_invocable_v<L, int>);
+    static_assert(!std::is_invocable_v<L, long>);
+    static_assert(!std::is_invocable_v<L, long long>);
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert( std::is_invocable_v<L, __uint128_t>, "");
-    static_assert(!std::is_invocable_v<L,  __int128_t>, "");
+    static_assert(!std::is_invocable_v<L, __int128_t>);
 #endif
 
-    static_assert(!std::is_invocable_v<L, A, unsigned>, "");
-    static_assert(!std::is_invocable_v<L, E1, unsigned>, "");
-    static_assert(!std::is_invocable_v<L, E2, unsigned>, "");
-    }
+    static_assert(!std::is_invocable_v<L, int8_t>);
+    static_assert(!std::is_invocable_v<L, int16_t>);
+    static_assert(!std::is_invocable_v<L, int32_t>);
+    static_assert(!std::is_invocable_v<L, int64_t>);
+    static_assert(!std::is_invocable_v<L, intmax_t>);
+    static_assert(!std::is_invocable_v<L, intptr_t>);
+    static_assert(!std::is_invocable_v<L, ptrdiff_t>);
+
+    static_assert(!std::is_invocable_v<L, bool>);
+    static_assert(!std::is_invocable_v<L, char>);
+    static_assert(!std::is_invocable_v<L, wchar_t>);
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
+    static_assert(!std::is_invocable_v<L, char8_t>);
+#endif
+    static_assert(!std::is_invocable_v<L, char16_t>);
+    static_assert(!std::is_invocable_v<L, char32_t>);
 
-    static_assert(constexpr_test<unsigned char>(),      "");
-    static_assert(constexpr_test<unsigned short>(),     "");
-    static_assert(constexpr_test<unsigned>(),           "");
-    static_assert(constexpr_test<unsigned long>(),      "");
-    static_assert(constexpr_test<unsigned long long>(), "");
-
-    static_assert(constexpr_test<uint8_t>(),   "");
-    static_assert(constexpr_test<uint16_t>(),  "");
-    static_assert(constexpr_test<uint32_t>(),  "");
-    static_assert(constexpr_test<uint64_t>(),  "");
-    static_assert(constexpr_test<size_t>(),    "");
-    static_assert(constexpr_test<uintmax_t>(), "");
-    static_assert(constexpr_test<uintptr_t>(), "");
+    static_assert(!std::is_invocable_v<L, A>);
+    static_assert(!std::is_invocable_v<L, A*>);
+    static_assert(!std::is_invocable_v<L, E1>);
+    static_assert(!std::is_invocable_v<L, E2>);
+    }
 
+    static_assert(test<unsigned char>());
+    static_assert(test<unsigned short>());
+    static_assert(test<unsigned int>());
+    static_assert(test<unsigned long>());
+    static_assert(test<unsigned long long>());
 #ifndef _LIBCPP_HAS_NO_INT128
-    static_assert(constexpr_test<__uint128_t>(),        "");
+    static_assert(test<__uint128_t>());
 #endif
 
-
-    runtime_test<unsigned char>();
-    runtime_test<unsigned>();
-    runtime_test<unsigned short>();
-    runtime_test<unsigned long>();
-    runtime_test<unsigned long long>();
-
-    runtime_test<uint8_t>();
-    runtime_test<uint16_t>();
-    runtime_test<uint32_t>();
-    runtime_test<uint64_t>();
-    runtime_test<size_t>();
-    runtime_test<uintmax_t>();
-    runtime_test<uintptr_t>();
-
-
+    static_assert(test<uint8_t>());
+    static_assert(test<uint16_t>());
+    static_assert(test<uint32_t>());
+    static_assert(test<uint64_t>());
+    static_assert(test<uintmax_t>());
+    static_assert(test<uintptr_t>());
+    static_assert(test<size_t>());
+
+    test<unsigned char>();
+    test<unsigned short>();
+    test<unsigned int>();
+    test<unsigned long>();
+    test<unsigned long long>();
 #ifndef _LIBCPP_HAS_NO_INT128
-    runtime_test<__uint128_t>();
+    test<__uint128_t>();
+#endif
 
-    {
-    __uint128_t val = 168; // 0xA8 (aka 10101000)
+    test<uint8_t>();
+    test<uint16_t>();
+    test<uint32_t>();
+    test<uint64_t>();
+    test<uintmax_t>();
+    test<uintptr_t>();
+    test<size_t>();
 
-    assert( std::rotr(val, 128) == 168);
-    val <<= 32;
-    assert( std::rotr(val,  32) == 168);
-    val <<= 2;
-    assert( std::rotr(val,  33) == 336);
-    val <<= 3;
-    assert( std::rotr(val,  38) ==  84);
-    assert( std::rotr(val, 166) ==  84);
-    }
+#ifndef _LIBCPP_HAS_NO_INT128
+    test_uint128();
+    static_assert(test_uint128());
 #endif
 
     return 0;
 }