diff --git a/libcxx/docs/Cxx2aStatus.rst b/libcxx/docs/Cxx2aStatus.rst
--- a/libcxx/docs/Cxx2aStatus.rst
+++ b/libcxx/docs/Cxx2aStatus.rst
@@ -40,6 +40,7 @@
.. [#note-P0202] P0202: The missing bits in P0202 are in ``copy`` and ``copy_backwards`` (and the ones that call them: ``copy_n``, ``set_union``, ``set_difference``, and ``set_symmetric_difference``). This is because the first two algorithms have specializations that call ``memmove`` which is not constexpr. See `Bug 25165 <https://bugs.llvm.org/show_bug.cgi?id=25165>`__
.. [#note-P0600] P0600: The missing bits in P0600 are in |sect|\ [mem.res.class], |sect|\ [mem.poly.allocator.class], and |sect|\ [container.node.overview].
+ .. [#note-P0966] P0966: It was previously erroneously marked as complete in version 8.0. See `bug 45368 <https://llvm.org/PR45368>`__.
.. [#note-P0619] P0619: Only ``std::allocator`` part is implemented.
diff --git a/libcxx/docs/Cxx2aStatusPaperStatus.csv b/libcxx/docs/Cxx2aStatusPaperStatus.csv
--- a/libcxx/docs/Cxx2aStatusPaperStatus.csv
+++ b/libcxx/docs/Cxx2aStatusPaperStatus.csv
@@ -24,7 +24,7 @@
"`P0809R0 <https://wg21.link/P0809R0>`__","LWG","Comparing Unordered Containers","Jacksonville","",""
"`P0858R0 <https://wg21.link/P0858R0>`__","LWG","Constexpr iterator requirements","Jacksonville","",""
"`P0905R1 <https://wg21.link/P0905R1>`__","CWG","Symmetry for spaceship","Jacksonville","",""
-"`P0966R1 <https://wg21.link/P0966R1>`__","LWG","``string::reserve``\ Should Not Shrink","Jacksonville","|Complete|","8.0"
+"`P0966R1 <https://wg21.link/P0966R1>`__","LWG","``string::reserve``\ Should Not Shrink","Jacksonville","|Complete| [#note-P0966]_","12.0"
"","","","","",""
"`P0019R8 <https://wg21.link/P0019R8>`__","LWG","Atomic Ref","Rapperswil","",""
"`P0458R2 <https://wg21.link/P0458R2>`__","LWG","Checking for Existence of an Element in Associative Containers","Rapperswil","|Complete|",""
diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -991,6 +991,12 @@
# define _LIBCPP_DEPRECATED_IN_CXX17
#endif
+#if _LIBCPP_STD_VER > 17
+# define _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_DEPRECATED
+#else
+# define _LIBCPP_DEPRECATED_IN_CXX20
+#endif
+
// Macros to enter and leave a state where deprecation warnings are suppressed.
#if !defined(_LIBCPP_SUPPRESS_DEPRECATED_PUSH) && \
(defined(_LIBCPP_COMPILER_CLANG) || defined(_LIBCPP_COMPILER_GCC))
diff --git a/libcxx/include/string b/libcxx/include/string
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -153,7 +153,8 @@
void resize(size_type n, value_type c);
void resize(size_type n);
- void reserve(size_type res_arg = 0);
+ void reserve(size_type res_arg);
+ void reserve(); // deprecated in C++20
void shrink_to_fit();
void clear() noexcept;
bool empty() const noexcept;
@@ -954,13 +955,13 @@
void resize(size_type __n, value_type __c);
_LIBCPP_INLINE_VISIBILITY void resize(size_type __n) {resize(__n, value_type());}
- void reserve(size_type __res_arg);
+ void reserve(size_type __requested_capacity);
_LIBCPP_INLINE_VISIBILITY void __resize_default_init(size_type __n);
+ _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_INLINE_VISIBILITY
+ void reserve() _NOEXCEPT {shrink_to_fit();}
_LIBCPP_INLINE_VISIBILITY
- void reserve() _NOEXCEPT {reserve(0);}
- _LIBCPP_INLINE_VISIBILITY
- void shrink_to_fit() _NOEXCEPT {reserve();}
+ void shrink_to_fit() _NOEXCEPT;
_LIBCPP_INLINE_VISIBILITY
void clear() _NOEXCEPT;
_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
@@ -1418,6 +1419,8 @@
_LIBCPP_INLINE_VISIBILITY void __clear_and_shrink() _NOEXCEPT;
+ _LIBCPP_INLINE_VISIBILITY void __shrink_or_extend(size_type __target_capacity);
+
_LIBCPP_INLINE_VISIBILITY
bool __is_long() const _NOEXCEPT
{return bool(__r_.first().__s.__size_ & __short_mask);}
@@ -3262,65 +3265,88 @@
template <class _CharT, class _Traits, class _Allocator>
void
-basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __res_arg)
+basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __requested_capacity)
{
- if (__res_arg > max_size())
+ if (__requested_capacity > max_size())
this->__throw_length_error();
+
+#if _LIBCPP_STD_VER > 17
+ // Reserve never shrinks as of C++20.
+ if (__requested_capacity <= capacity()) return;
+#endif
+
+ size_type __target_capacity = _VSTD::max(__requested_capacity, size());
+ __target_capacity = __recommend(__target_capacity);
+ if (__target_capacity == capacity()) return;
+
+ __shrink_or_extend(__target_capacity);
+}
+
+template <class _CharT, class _Traits, class _Allocator>
+void
+basic_string<_CharT, _Traits, _Allocator>::shrink_to_fit() _NOEXCEPT
+{
+ size_type __target_capacity = __recommend(size());
+ if (__target_capacity == capacity()) return;
+
+ __shrink_or_extend(__target_capacity);
+}
+
+template <class _CharT, class _Traits, class _Allocator>
+void
+basic_string<_CharT, _Traits, _Allocator>::__shrink_or_extend(size_type __target_capacity)
+{
size_type __cap = capacity();
size_type __sz = size();
- __res_arg = _VSTD::max(__res_arg, __sz);
- __res_arg = __recommend(__res_arg);
- if (__res_arg != __cap)
+
+ pointer __new_data, __p;
+ bool __was_long, __now_long;
+ if (__target_capacity == __min_cap - 1)
{
- pointer __new_data, __p;
- bool __was_long, __now_long;
- if (__res_arg == __min_cap - 1)
- {
- __was_long = true;
- __now_long = false;
- __new_data = __get_short_pointer();
- __p = __get_long_pointer();
- }
+ __was_long = true;
+ __now_long = false;
+ __new_data = __get_short_pointer();
+ __p = __get_long_pointer();
+ }
+ else
+ {
+ if (__target_capacity > __cap)
+ __new_data = __alloc_traits::allocate(__alloc(), __target_capacity+1);
else
{
- if (__res_arg > __cap)
- __new_data = __alloc_traits::allocate(__alloc(), __res_arg+1);
- else
+ #ifndef _LIBCPP_NO_EXCEPTIONS
+ try
{
- #ifndef _LIBCPP_NO_EXCEPTIONS
- try
- {
- #endif // _LIBCPP_NO_EXCEPTIONS
- __new_data = __alloc_traits::allocate(__alloc(), __res_arg+1);
- #ifndef _LIBCPP_NO_EXCEPTIONS
- }
- catch (...)
- {
- return;
- }
- #else // _LIBCPP_NO_EXCEPTIONS
- if (__new_data == nullptr)
- return;
- #endif // _LIBCPP_NO_EXCEPTIONS
+ #endif // _LIBCPP_NO_EXCEPTIONS
+ __new_data = __alloc_traits::allocate(__alloc(), __target_capacity+1);
+ #ifndef _LIBCPP_NO_EXCEPTIONS
}
- __now_long = true;
- __was_long = __is_long();
- __p = __get_pointer();
- }
- traits_type::copy(_VSTD::__to_address(__new_data),
- _VSTD::__to_address(__p), size()+1);
- if (__was_long)
- __alloc_traits::deallocate(__alloc(), __p, __cap+1);
- if (__now_long)
- {
- __set_long_cap(__res_arg+1);
- __set_long_size(__sz);
- __set_long_pointer(__new_data);
+ catch (...)
+ {
+ return;
+ }
+ #else // _LIBCPP_NO_EXCEPTIONS
+ if (__new_data == nullptr)
+ return;
+ #endif // _LIBCPP_NO_EXCEPTIONS
}
- else
- __set_short_size(__sz);
- __invalidate_all_iterators();
+ __now_long = true;
+ __was_long = __is_long();
+ __p = __get_pointer();
+ }
+ traits_type::copy(_VSTD::__to_address(__new_data),
+ _VSTD::__to_address(__p), size()+1);
+ if (__was_long)
+ __alloc_traits::deallocate(__alloc(), __p, __cap+1);
+ if (__now_long)
+ {
+ __set_long_cap(__target_capacity+1);
+ __set_long_size(__sz);
+ __set_long_pointer(__new_data);
}
+ else
+ __set_short_size(__sz);
+ __invalidate_all_iterators();
}
template <class _CharT, class _Traits, class _Allocator>
diff --git a/libcxx/test/libcxx/strings/basic.string/string.capacity/reserve.pass.cpp b/libcxx/test/libcxx/strings/basic.string/string.capacity/reserve.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/libcxx/strings/basic.string/string.capacity/reserve.pass.cpp
@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void reserve(); // Deprecated in C++20.
+
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+#include "test_macros.h"
+#include "min_allocator.h"
+
+template <class S>
+void
+test()
+{
+ // Tests that a call to reserve() on a long string is equivalent to shrink_to_fit().
+ S s(1000, 'a');
+ typename S::size_type old_cap = s.capacity();
+ s.resize(20);
+ assert(s.capacity() == old_cap);
+ s.reserve();
+ assert(s.capacity() < old_cap);
+}
+
+int main(int, char**)
+{
+ {
+ typedef std::string S;
+ test<S>();
+ }
+#if TEST_STD_VER >= 11
+ {
+ typedef min_allocator<char> A;
+ typedef std::basic_string<char, std::char_traits<char>, A> S;
+ test<S>();
+ }
+#endif
+
+ return 0;
+}
diff --git a/libcxx/test/std/strings/basic.string/string.capacity/reserve.deprecated_in_cxx20.verify.cpp b/libcxx/test/std/strings/basic.string/string.capacity/reserve.deprecated_in_cxx20.verify.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/strings/basic.string/string.capacity/reserve.deprecated_in_cxx20.verify.cpp
@@ -0,0 +1,22 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// void reserve(); // Deprecated in C++20
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+#include <string>
+
+int main(int, char**)
+{
+ std::string s;
+ s.reserve(); // expected-warning {{'reserve' is deprecated}}
+ return 0;
+}
diff --git a/libcxx/test/std/strings/basic.string/string.capacity/reserve.pass.cpp b/libcxx/test/std/strings/basic.string/string.capacity/reserve.pass.cpp
--- a/libcxx/test/std/strings/basic.string/string.capacity/reserve.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.capacity/reserve.pass.cpp
@@ -8,9 +8,9 @@
// <string>
-// Split into two calls for C++20
-// void reserve();
-// void reserve(size_type res_arg);
+// void reserve(); // Deprecated in C++20.
+
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
#include <string>
#include <stdexcept>
@@ -21,8 +21,13 @@
template <class S>
void
-test(S s)
+test(typename S::size_type min_cap, typename S::size_type erased_index)
{
+ S s(min_cap, 'a');
+ s.erase(erased_index);
+ assert(s.size() == erased_index);
+ assert(s.capacity() >= min_cap); // Check that we really have at least this capacity.
+
typename S::size_type old_cap = s.capacity();
S s0 = s;
s.reserve();
@@ -32,102 +37,23 @@
assert(s.capacity() >= s.size());
}
-template <class S>
-void
-test(S s, typename S::size_type res_arg)
-{
- typename S::size_type old_cap = s.capacity();
- ((void)old_cap); // Prevent unused warning
- S s0 = s;
- if (res_arg <= s.max_size())
- {
- s.reserve(res_arg);
- assert(s == s0);
- assert(s.capacity() >= res_arg);
- assert(s.capacity() >= s.size());
-#if TEST_STD_VER > 17
- assert(s.capacity() >= old_cap); // resize never shrinks as of P0966
-#endif
- }
-#ifndef TEST_HAS_NO_EXCEPTIONS
- else
- {
- try
- {
- s.reserve(res_arg);
- assert(false);
- }
- catch (std::length_error&)
- {
- assert(res_arg > s.max_size());
- }
- }
-#endif
-}
-
int main(int, char**)
{
{
typedef std::string S;
{
- S s;
- test(s);
-
- s.assign(10, 'a');
- s.erase(5);
- test(s);
-
- s.assign(100, 'a');
- s.erase(50);
- test(s);
- }
- {
- S s;
- test(s, 5);
- test(s, 10);
- test(s, 50);
- }
- {
- S s(100, 'a');
- s.erase(50);
- test(s, 5);
- test(s, 10);
- test(s, 50);
- test(s, 100);
- test(s, 1000);
- test(s, S::npos);
+ test<S>(0, 0);
+ test<S>(10, 5);
+ test<S>(100, 50);
}
}
#if TEST_STD_VER >= 11
{
typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
{
- S s;
- test(s);
-
- s.assign(10, 'a');
- s.erase(5);
- test(s);
-
- s.assign(100, 'a');
- s.erase(50);
- test(s);
- }
- {
- S s;
- test(s, 5);
- test(s, 10);
- test(s, 50);
- }
- {
- S s(100, 'a');
- s.erase(50);
- test(s, 5);
- test(s, 10);
- test(s, 50);
- test(s, 100);
- test(s, 1000);
- test(s, S::npos);
+ test<S>(0, 0);
+ test<S>(10, 5);
+ test<S>(100, 50);
}
}
#endif
diff --git a/libcxx/test/std/strings/basic.string/string.capacity/reserve.pass.cpp b/libcxx/test/std/strings/basic.string/string.capacity/reserve_size.pass.cpp
copy from libcxx/test/std/strings/basic.string/string.capacity/reserve.pass.cpp
copy to libcxx/test/std/strings/basic.string/string.capacity/reserve_size.pass.cpp
--- a/libcxx/test/std/strings/basic.string/string.capacity/reserve.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.capacity/reserve_size.pass.cpp
@@ -8,10 +8,19 @@
// <string>
-// Split into two calls for C++20
-// void reserve();
// void reserve(size_type res_arg);
+// This test relies on https://llvm.org/PR45368 being fixed, which isn't in
+// older Apple dylibs
+//
+// XFAIL: with_system_cxx_lib=macosx10.15
+// XFAIL: with_system_cxx_lib=macosx10.14
+// XFAIL: with_system_cxx_lib=macosx10.13
+// XFAIL: with_system_cxx_lib=macosx10.12
+// XFAIL: with_system_cxx_lib=macosx10.11
+// XFAIL: with_system_cxx_lib=macosx10.10
+// XFAIL: with_system_cxx_lib=macosx10.9
+
#include <string>
#include <stdexcept>
#include <cassert>
@@ -21,32 +30,26 @@
template <class S>
void
-test(S s)
+test(typename S::size_type min_cap, typename S::size_type erased_index, typename S::size_type res_arg)
{
- typename S::size_type old_cap = s.capacity();
- S s0 = s;
- s.reserve();
- LIBCPP_ASSERT(s.__invariants());
- assert(s == s0);
- assert(s.capacity() <= old_cap);
- assert(s.capacity() >= s.size());
-}
+ S s(min_cap, 'a');
+ s.erase(erased_index);
+ assert(s.size() == erased_index);
+ assert(s.capacity() >= min_cap); // Check that we really have at least this capacity.
-template <class S>
-void
-test(S s, typename S::size_type res_arg)
-{
+#if TEST_STD_VER > 17
typename S::size_type old_cap = s.capacity();
- ((void)old_cap); // Prevent unused warning
+#endif
S s0 = s;
if (res_arg <= s.max_size())
{
s.reserve(res_arg);
+ LIBCPP_ASSERT(s.__invariants());
assert(s == s0);
assert(s.capacity() >= res_arg);
assert(s.capacity() >= s.size());
#if TEST_STD_VER > 17
- assert(s.capacity() >= old_cap); // resize never shrinks as of P0966
+ assert(s.capacity() >= old_cap); // reserve never shrinks as of P0966 (C++20)
#endif
}
#ifndef TEST_HAS_NO_EXCEPTIONS
@@ -55,6 +58,7 @@
try
{
s.reserve(res_arg);
+ LIBCPP_ASSERT(s.__invariants());
assert(false);
}
catch (std::length_error&)
@@ -70,64 +74,34 @@
{
typedef std::string S;
{
- S s;
- test(s);
-
- s.assign(10, 'a');
- s.erase(5);
- test(s);
-
- s.assign(100, 'a');
- s.erase(50);
- test(s);
- }
- {
- S s;
- test(s, 5);
- test(s, 10);
- test(s, 50);
+ test<S>(0, 0, 5);
+ test<S>(0, 0, 10);
+ test<S>(0, 0, 50);
}
{
- S s(100, 'a');
- s.erase(50);
- test(s, 5);
- test(s, 10);
- test(s, 50);
- test(s, 100);
- test(s, 1000);
- test(s, S::npos);
+ test<S>(100, 50, 5);
+ test<S>(100, 50, 10);
+ test<S>(100, 50, 50);
+ test<S>(100, 50, 100);
+ test<S>(100, 50, 1000);
+ test<S>(100, 50, S::npos);
}
}
#if TEST_STD_VER >= 11
{
typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
{
- S s;
- test(s);
-
- s.assign(10, 'a');
- s.erase(5);
- test(s);
-
- s.assign(100, 'a');
- s.erase(50);
- test(s);
- }
- {
- S s;
- test(s, 5);
- test(s, 10);
- test(s, 50);
+ test<S>(0, 0, 5);
+ test<S>(0, 0, 10);
+ test<S>(0, 0, 50);
}
{
- S s(100, 'a');
- s.erase(50);
- test(s, 5);
- test(s, 10);
- test(s, 50);
- test(s, 100);
- test(s, 1000);
- test(s, S::npos);
+ test<S>(100, 50, 5);
+ test<S>(100, 50, 10);
+ test<S>(100, 50, 50);
+ test<S>(100, 50, 100);
+ test<S>(100, 50, 1000);
+ test<S>(100, 50, S::npos);
}
}
#endif