[libc++][NFC] Refactor the enable_ifs in the math headers

[Mordante]

LGTM! I would mark the patch as NFC to indicate no changes are intended.

[philnik]

Rebased

[philnik]

Rebased

[philnik]

Rebased

[philnik]

Try to fix CI

[philnik]

Rebased

libcxx/include/__math/abs.h

 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double fabs(double __x) _NOEXCEPT {
   return __builtin_fabs(__x);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double fabs(long double __x) _NOEXCEPT {
   return __builtin_fabsl(__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-fabs(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI double fabs(_A1 __x) _NOEXCEPT {
   return __builtin_fabs((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_ABS_H

libcxx/include/__math/copysign.h

 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI float copysign(float __x, float __y) _NOEXCEPT {
   return ::__builtin_copysignf(__x, __y);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double copysign(long double __x, long double __y) _NOEXCEPT {
   return ::__builtin_copysignl(__x, __y);
 }
 
-template <class _A1, class _A2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    copysign(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type
   return ::__builtin_copysign(__x, __y);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_COPYSIGN_H

libcxx/include/__math/error_functions.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double erf(double __x) _NOEXCEPT {
   return __builtin_erf(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double erf(long double __x) _NOEXCEPT { return __builtin_erfl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type erf(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double erf(_A1 __x) _NOEXCEPT {
   return __builtin_erf((double)__x);
 }
 
 // erfc
 
 inline _LIBCPP_HIDE_FROM_ABI float erfc(float __x) _NOEXCEPT { return __builtin_erfcf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double erfc(double __x) _NOEXCEPT {
   return __builtin_erfc(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double erfc(long double __x) _NOEXCEPT { return __builtin_erfcl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type erfc(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double erfc(_A1 __x) _NOEXCEPT {
   return __builtin_erfc((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_ERROR_FUNCTIONS_H

libcxx/include/__math/exponential_functions.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double exp(double __x) _NOEXCEPT {
   return __builtin_exp(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double exp(long double __x) _NOEXCEPT { return __builtin_expl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type exp(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double exp(_A1 __x) _NOEXCEPT {
   return __builtin_exp((double)__x);
 }
 
 // frexp
 
 inline _LIBCPP_HIDE_FROM_ABI float frexp(float __x, int* __e) _NOEXCEPT { return __builtin_frexpf(__x, __e); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double frexp(double __x, int* __e) _NOEXCEPT {
   return __builtin_frexp(__x, __e);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double frexp(long double __x, int* __e) _NOEXCEPT {
   return __builtin_frexpl(__x, __e);
 }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-frexp(_A1 __x, int* __e) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double frexp(_A1 __x, int* __e) _NOEXCEPT {
   return __builtin_frexp((double)__x, __e);
 }
 
 // ldexp
 
 inline _LIBCPP_HIDE_FROM_ABI float ldexp(float __x, int __e) _NOEXCEPT { return __builtin_ldexpf(__x, __e); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double ldexp(double __x, int __e) _NOEXCEPT {
   return __builtin_ldexp(__x, __e);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double ldexp(long double __x, int __e) _NOEXCEPT {
   return __builtin_ldexpl(__x, __e);
 }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-ldexp(_A1 __x, int __e) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double ldexp(_A1 __x, int __e) _NOEXCEPT {
   return __builtin_ldexp((double)__x, __e);
 }
 
 // exp2
 
 inline _LIBCPP_HIDE_FROM_ABI float exp2(float __x) _NOEXCEPT { return __builtin_exp2f(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double exp2(double __x) _NOEXCEPT {
   return __builtin_exp2(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double exp2(long double __x) _NOEXCEPT { return __builtin_exp2l(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type exp2(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double exp2(_A1 __x) _NOEXCEPT {
   return __builtin_exp2((double)__x);
 }
 
 // expm1
 
 inline _LIBCPP_HIDE_FROM_ABI float expm1(float __x) _NOEXCEPT { return __builtin_expm1f(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double expm1(double __x) _NOEXCEPT {
   return __builtin_expm1(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double expm1(long double __x) _NOEXCEPT { return __builtin_expm1l(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type expm1(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double expm1(_A1 __x) _NOEXCEPT {
   return __builtin_expm1((double)__x);
 }
 
 // scalbln
 
 inline _LIBCPP_HIDE_FROM_ABI float scalbln(float __x, long __y) _NOEXCEPT { return __builtin_scalblnf(__x, __y); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double scalbln(double __x, long __y) _NOEXCEPT {
   return __builtin_scalbln(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double scalbln(long double __x, long __y) _NOEXCEPT {
   return __builtin_scalblnl(__x, __y);
 }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-scalbln(_A1 __x, long __y) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double scalbln(_A1 __x, long __y) _NOEXCEPT {
   return __builtin_scalbln((double)__x, __y);
 }
 
 // scalbn
 
 inline _LIBCPP_HIDE_FROM_ABI float scalbn(float __x, int __y) _NOEXCEPT { return __builtin_scalbnf(__x, __y); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double scalbn(double __x, int __y) _NOEXCEPT {
   return __builtin_scalbn(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double scalbn(long double __x, int __y) _NOEXCEPT {
   return __builtin_scalbnl(__x, __y);
 }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-scalbn(_A1 __x, int __y) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double scalbn(_A1 __x, int __y) _NOEXCEPT {
   return __builtin_scalbn((double)__x, __y);
 }
 
 // pow
 
 inline _LIBCPP_HIDE_FROM_ABI float pow(float __x, float __y) _NOEXCEPT { return __builtin_powf(__x, __y); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double pow(double __x, double __y) _NOEXCEPT {
   return __builtin_pow(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double pow(long double __x, long double __y) _NOEXCEPT {
   return __builtin_powl(__x, __y);
 }
 
-template <class _A1, class _A2>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    pow(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type pow(_A1 __x, _A2 __y) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::pow((__result_type)__x, (__result_type)__y);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_EXPONENTIAL_FUNCTIONS_H

libcxx/include/__math/fdim.h

 _LIBCPP_HIDE_FROM_ABI double fdim(double __x, double __y) _NOEXCEPT {
   return __builtin_fdim(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double fdim(long double __x, long double __y) _NOEXCEPT {
   return __builtin_fdiml(__x, __y);
 }
 
-template <class _A1, class _A2>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    fdim(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type fdim(_A1 __x, _A2 __y) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::fdim((__result_type)__x, (__result_type)__y);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_FDIM_H

libcxx/include/__math/fma.h

 _LIBCPP_HIDE_FROM_ABI double fma(double __x, double __y, double __z) _NOEXCEPT {
   return __builtin_fma(__x, __y, __z);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double fma(long double __x, long double __y, long double __z) _NOEXCEPT {
   return __builtin_fmal(__x, __y, __z);
 }
 
-template <class _A1, class _A2, class _A3>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value && is_arithmetic<_A3>::value,
-                            __promote<_A1, _A2, _A3> >::type
-    fma(_A1 __x, _A2 __y, _A3 __z) _NOEXCEPT {
+template <class _A1,
+          class _A2,
+          class _A3,
+          __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value && is_arithmetic<_A3>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2, _A3>::type fma(_A1 __x, _A2 __y, _A3 __z) _NOEXCEPT {
   typedef typename __promote<_A1, _A2, _A3>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value &&
                    _IsSame<_A3, __result_type>::value)),
                 "");
   return __builtin_fma((__result_type)__x, (__result_type)__y, (__result_type)__z);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_FMA_H

libcxx/include/__math/gamma.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double lgamma(double __x) _NOEXCEPT {
   return __builtin_lgamma(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double lgamma(long double __x) _NOEXCEPT { return __builtin_lgammal(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type lgamma(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double lgamma(_A1 __x) _NOEXCEPT {
   return __builtin_lgamma((double)__x);
 }
 
 // nan
 
 // tgamma
 
 inline _LIBCPP_HIDE_FROM_ABI float tgamma(float __x) _NOEXCEPT { return __builtin_tgammaf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double tgamma(double __x) _NOEXCEPT {
   return __builtin_tgamma(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double tgamma(long double __x) _NOEXCEPT { return __builtin_tgammal(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type tgamma(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double tgamma(_A1 __x) _NOEXCEPT {
   return __builtin_tgamma((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_GAMMA_H

libcxx/include/__math/hyperbolic_functions.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double cosh(double __x) _NOEXCEPT {
   return __builtin_cosh(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double cosh(long double __x) _NOEXCEPT { return __builtin_coshl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type cosh(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double cosh(_A1 __x) _NOEXCEPT {
   return __builtin_cosh((double)__x);
 }
 
 // sinh
 
 inline _LIBCPP_HIDE_FROM_ABI float sinh(float __x) _NOEXCEPT { return __builtin_sinhf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double sinh(double __x) _NOEXCEPT {
   return __builtin_sinh(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double sinh(long double __x) _NOEXCEPT { return __builtin_sinhl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type sinh(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double sinh(_A1 __x) _NOEXCEPT {
   return __builtin_sinh((double)__x);
 }
 
 // tanh
 
 inline _LIBCPP_HIDE_FROM_ABI float tanh(float __x) _NOEXCEPT { return __builtin_tanhf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double tanh(double __x) _NOEXCEPT {
   return __builtin_tanh(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double tanh(long double __x) _NOEXCEPT { return __builtin_tanhl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type tanh(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double tanh(_A1 __x) _NOEXCEPT {
   return __builtin_tanh((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_HYPERBOLIC_FUNCTIONS_H

libcxx/include/__math/hypot.h

 _LIBCPP_HIDE_FROM_ABI double hypot(double __x, double __y) _NOEXCEPT {
   return __builtin_hypot(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double hypot(long double __x, long double __y) _NOEXCEPT {
   return __builtin_hypotl(__x, __y);
 }
 
-template <class _A1, class _A2>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    hypot(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type hypot(_A1 __x, _A2 __y) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::hypot((__result_type)__x, (__result_type)__y);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_HYPOT_H

libcxx/include/__math/inverse_hyperbolic_functions.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double acosh(double __x) _NOEXCEPT {
   return __builtin_acosh(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double acosh(long double __x) _NOEXCEPT { return __builtin_acoshl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type acosh(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double acosh(_A1 __x) _NOEXCEPT {
   return __builtin_acosh((double)__x);
 }
 
 // asinh
 
 inline _LIBCPP_HIDE_FROM_ABI float asinh(float __x) _NOEXCEPT { return __builtin_asinhf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double asinh(double __x) _NOEXCEPT {
   return __builtin_asinh(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double asinh(long double __x) _NOEXCEPT { return __builtin_asinhl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type asinh(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double asinh(_A1 __x) _NOEXCEPT {
   return __builtin_asinh((double)__x);
 }
 
 // atanh
 
 inline _LIBCPP_HIDE_FROM_ABI float atanh(float __x) _NOEXCEPT { return __builtin_atanhf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double atanh(double __x) _NOEXCEPT {
   return __builtin_atanh(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double atanh(long double __x) _NOEXCEPT { return __builtin_atanhl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type atanh(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double atanh(_A1 __x) _NOEXCEPT {
   return __builtin_atanh((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_INVERSE_HYPERBOLIC_FUNCTIONS_H

libcxx/include/__math/inverse_trigonometric_functions.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double acos(double __x) _NOEXCEPT {
   return __builtin_acos(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double acos(long double __x) _NOEXCEPT { return __builtin_acosl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type acos(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double acos(_A1 __x) _NOEXCEPT {
   return __builtin_acos((double)__x);
 }
 
 // asin
 
 inline _LIBCPP_HIDE_FROM_ABI float asin(float __x) _NOEXCEPT { return __builtin_asinf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double asin(double __x) _NOEXCEPT {
   return __builtin_asin(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double asin(long double __x) _NOEXCEPT { return __builtin_asinl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type asin(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double asin(_A1 __x) _NOEXCEPT {
   return __builtin_asin((double)__x);
 }
 
 // atan
 
 inline _LIBCPP_HIDE_FROM_ABI float atan(float __x) _NOEXCEPT { return __builtin_atanf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double atan(double __x) _NOEXCEPT {
   return __builtin_atan(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double atan(long double __x) _NOEXCEPT { return __builtin_atanl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type atan(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double atan(_A1 __x) _NOEXCEPT {
   return __builtin_atan((double)__x);
 }
 
 // atan2
 
 inline _LIBCPP_HIDE_FROM_ABI float atan2(float __y, float __x) _NOEXCEPT { return __builtin_atan2f(__y, __x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double atan2(double __x, double __y) _NOEXCEPT {
   return __builtin_atan2(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double atan2(long double __y, long double __x) _NOEXCEPT {
   return __builtin_atan2l(__y, __x);
 }
 
-template <class _A1, class _A2>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    atan2(_A1 __y, _A2 __x) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type atan2(_A1 __y, _A2 __x) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::atan2((__result_type)__y, (__result_type)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_INVERSE_TRIGONOMETRIC_FUNCTIONS_H

libcxx/include/__math/logarithms.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double log(double __x) _NOEXCEPT {
   return __builtin_log(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double log(long double __x) _NOEXCEPT { return __builtin_logl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type log(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double log(_A1 __x) _NOEXCEPT {
   return __builtin_log((double)__x);
 }
 
 // log10
 
 inline _LIBCPP_HIDE_FROM_ABI float log10(float __x) _NOEXCEPT { return __builtin_log10f(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double log10(double __x) _NOEXCEPT {
   return __builtin_log10(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double log10(long double __x) _NOEXCEPT { return __builtin_log10l(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type log10(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double log10(_A1 __x) _NOEXCEPT {
   return __builtin_log10((double)__x);
 }
 
 // ilogb
 
 inline _LIBCPP_HIDE_FROM_ABI int ilogb(float __x) _NOEXCEPT { return __builtin_ilogbf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double ilogb(double __x) _NOEXCEPT {
   return __builtin_ilogb(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI int ilogb(long double __x) _NOEXCEPT { return __builtin_ilogbl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, int>::type ilogb(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI int ilogb(_A1 __x) _NOEXCEPT {
   return __builtin_ilogb((double)__x);
 }
 
 // log1p
 
 inline _LIBCPP_HIDE_FROM_ABI float log1p(float __x) _NOEXCEPT { return __builtin_log1pf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double log1p(double __x) _NOEXCEPT {
   return __builtin_log1p(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double log1p(long double __x) _NOEXCEPT { return __builtin_log1pl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type log1p(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double log1p(_A1 __x) _NOEXCEPT {
   return __builtin_log1p((double)__x);
 }
 
 // log2
 
 inline _LIBCPP_HIDE_FROM_ABI float log2(float __x) _NOEXCEPT { return __builtin_log2f(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double log2(double __x) _NOEXCEPT {
   return __builtin_log2(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double log2(long double __x) _NOEXCEPT { return __builtin_log2l(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type log2(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double log2(_A1 __x) _NOEXCEPT {
   return __builtin_log2((double)__x);
 }
 
 // logb
 
 inline _LIBCPP_HIDE_FROM_ABI float logb(float __x) _NOEXCEPT { return __builtin_logbf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double logb(double __x) _NOEXCEPT {
   return __builtin_logb(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double logb(long double __x) _NOEXCEPT { return __builtin_logbl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type logb(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double logb(_A1 __x) _NOEXCEPT {
   return __builtin_logb((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_LOGARITHMS_H

libcxx/include/__math/min_max.h

 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double fmax(double __x, double __y) _NOEXCEPT {
   return __builtin_fmax(__x, __y);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double fmax(long double __x, long double __y) _NOEXCEPT {
   return __builtin_fmaxl(__x, __y);
 }
 
-template <class _A1, class _A2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    fmax(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type fmax(_A1 __x, _A2 __y) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::fmax((__result_type)__x, (__result_type)__y);
 }
 
 // fmin
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI float fmin(float __x, float __y) _NOEXCEPT {
   return __builtin_fminf(__x, __y);
 }
 
 template <class = int>
 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double fmin(double __x, double __y) _NOEXCEPT {
   return __builtin_fmin(__x, __y);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double fmin(long double __x, long double __y) _NOEXCEPT {
   return __builtin_fminl(__x, __y);
 }
 
-template <class _A1, class _A2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    fmin(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type fmin(_A1 __x, _A2 __y) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::fmin((__result_type)__x, (__result_type)__y);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_MIN_MAX_H

libcxx/include/__math/modulo.h

 _LIBCPP_HIDE_FROM_ABI double fmod(double __x, double __y) _NOEXCEPT {
   return __builtin_fmod(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double fmod(long double __x, long double __y) _NOEXCEPT {
   return __builtin_fmodl(__x, __y);
 }
 
-template <class _A1, class _A2>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    fmod(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type fmod(_A1 __x, _A2 __y) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::fmod((__result_type)__x, (__result_type)__y);
 }
 
 // modf
 
 inline _LIBCPP_HIDE_FROM_ABI float modf(float __x, float* __y) _NOEXCEPT { return __builtin_modff(__x, __y); }

libcxx/include/__math/remainder.h

 _LIBCPP_HIDE_FROM_ABI double remainder(double __x, double __y) _NOEXCEPT {
   return __builtin_remainder(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double remainder(long double __x, long double __y) _NOEXCEPT {
   return __builtin_remainderl(__x, __y);
 }
 
-template <class _A1, class _A2>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    remainder(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type remainder(_A1 __x, _A2 __y) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::remainder((__result_type)__x, (__result_type)__y);
 }
 
 // remquo
 
 inline _LIBCPP_HIDE_FROM_ABI float remquo(float __x, float __y, int* __z) _NOEXCEPT {
   return __builtin_remquof(__x, __y, __z);
 }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double remquo(double __x, double __y, int* __z) _NOEXCEPT {
   return __builtin_remquo(__x, __y, __z);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double remquo(long double __x, long double __y, int* __z) _NOEXCEPT {
   return __builtin_remquol(__x, __y, __z);
 }
 
-template <class _A1, class _A2>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    remquo(_A1 __x, _A2 __y, int* __z) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type remquo(_A1 __x, _A2 __y, int* __z) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::remquo((__result_type)__x, (__result_type)__y, __z);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_REMAINDER_H

libcxx/include/__math/roots.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double sqrt(double __x) _NOEXCEPT {
   return __builtin_sqrt(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double sqrt(long double __x) _NOEXCEPT { return __builtin_sqrtl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type sqrt(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double sqrt(_A1 __x) _NOEXCEPT {
   return __builtin_sqrt((double)__x);
 }
 
 // cbrt
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI float cbrt(float __x) _NOEXCEPT { return __builtin_cbrtf(__x); }
 
 template <class = int>
 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double cbrt(double __x) _NOEXCEPT {
   return __builtin_cbrt(__x);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double cbrt(long double __x) _NOEXCEPT {
   return __builtin_cbrtl(__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-cbrt(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI double cbrt(_A1 __x) _NOEXCEPT {
   return __builtin_cbrt((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_ROOTS_H

libcxx/include/__math/rounding_functions.h

 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double ceil(double __x) _NOEXCEPT {
   return __builtin_ceil(__x);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double ceil(long double __x) _NOEXCEPT {
   return __builtin_ceill(__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-ceil(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI double ceil(_A1 __x) _NOEXCEPT {
   return __builtin_ceil((double)__x);
 }
 
 // floor
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI float floor(float __x) _NOEXCEPT { return __builtin_floorf(__x); }
 
 template <class = int>
 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double floor(double __x) _NOEXCEPT {
   return __builtin_floor(__x);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double floor(long double __x) _NOEXCEPT {
   return __builtin_floorl(__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-floor(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI double floor(_A1 __x) _NOEXCEPT {
   return __builtin_floor((double)__x);
 }
 
 // llrint
 
 inline _LIBCPP_HIDE_FROM_ABI long long llrint(float __x) _NOEXCEPT { return __builtin_llrintf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI long long llrint(double __x) _NOEXCEPT {
   return __builtin_llrint(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long long llrint(long double __x) _NOEXCEPT { return __builtin_llrintl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, long long>::type llrint(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI long long llrint(_A1 __x) _NOEXCEPT {
   return __builtin_llrint((double)__x);
 }
 
 // llround
 
 inline _LIBCPP_HIDE_FROM_ABI long long llround(float __x) _NOEXCEPT { return __builtin_llroundf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI long long llround(double __x) _NOEXCEPT {
   return __builtin_llround(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long long llround(long double __x) _NOEXCEPT { return __builtin_llroundl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, long long>::type llround(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI long long llround(_A1 __x) _NOEXCEPT {
   return __builtin_llround((double)__x);
 }
 
 // lrint
 
 inline _LIBCPP_HIDE_FROM_ABI long lrint(float __x) _NOEXCEPT { return __builtin_lrintf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI long lrint(double __x) _NOEXCEPT {
   return __builtin_lrint(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long lrint(long double __x) _NOEXCEPT { return __builtin_lrintl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, long>::type lrint(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI long lrint(_A1 __x) _NOEXCEPT {
   return __builtin_lrint((double)__x);
 }
 
 // lround
 
 inline _LIBCPP_HIDE_FROM_ABI long lround(float __x) _NOEXCEPT { return __builtin_lroundf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI long lround(double __x) _NOEXCEPT {
   return __builtin_lround(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long lround(long double __x) _NOEXCEPT { return __builtin_lroundl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, long>::type lround(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI long lround(_A1 __x) _NOEXCEPT {
   return __builtin_lround((double)__x);
 }
 
 // nearbyint
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI float nearbyint(float __x) _NOEXCEPT {
   return __builtin_nearbyintf(__x);
 }
 
 template <class = int>
 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double nearbyint(double __x) _NOEXCEPT {
   return __builtin_nearbyint(__x);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double nearbyint(long double __x) _NOEXCEPT {
   return __builtin_nearbyintl(__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-nearbyint(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI double nearbyint(_A1 __x) _NOEXCEPT {
   return __builtin_nearbyint((double)__x);
 }
 
 // nextafter
 
 inline _LIBCPP_HIDE_FROM_ABI float nextafter(float __x, float __y) _NOEXCEPT { return __builtin_nextafterf(__x, __y); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double nextafter(double __x, double __y) _NOEXCEPT {
   return __builtin_nextafter(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double nextafter(long double __x, long double __y) _NOEXCEPT {
   return __builtin_nextafterl(__x, __y);
 }
 
-template <class _A1, class _A2>
-inline _LIBCPP_HIDE_FROM_ABI
-    typename __enable_if_t< is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, __promote<_A1, _A2> >::type
-    nextafter(_A1 __x, _A2 __y) _NOEXCEPT {
+template <class _A1, class _A2, __enable_if_t<is_arithmetic<_A1>::value && is_arithmetic<_A2>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI typename __promote<_A1, _A2>::type nextafter(_A1 __x, _A2 __y) _NOEXCEPT {
   typedef typename __promote<_A1, _A2>::type __result_type;
   static_assert((!(_IsSame<_A1, __result_type>::value && _IsSame<_A2, __result_type>::value)), "");
   return __math::nextafter((__result_type)__x, (__result_type)__y);
 }
 
 // nexttoward
 
 inline _LIBCPP_HIDE_FROM_ABI float nexttoward(float __x, long double __y) _NOEXCEPT {
   return __builtin_nexttowardf(__x, __y);
 }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double nexttoward(double __x, long double __y) _NOEXCEPT {
   return __builtin_nexttoward(__x, __y);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double nexttoward(long double __x, long double __y) _NOEXCEPT {
   return __builtin_nexttowardl(__x, __y);
 }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-nexttoward(_A1 __x, long double __y) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double nexttoward(_A1 __x, long double __y) _NOEXCEPT {
   return __builtin_nexttoward((double)__x, __y);
 }
 
 // rint
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI float rint(float __x) _NOEXCEPT { return __builtin_rintf(__x); }
 
 template <class = int>
 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double rint(double __x) _NOEXCEPT {
   return __builtin_rint(__x);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double rint(long double __x) _NOEXCEPT {
   return __builtin_rintl(__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-rint(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI double rint(_A1 __x) _NOEXCEPT {
   return __builtin_rint((double)__x);
 }
 
 // round
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI float round(float __x) _NOEXCEPT { return __builtin_round(__x); }
 
 template <class = int>
 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double round(double __x) _NOEXCEPT {
   return __builtin_round(__x);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double round(long double __x) _NOEXCEPT {
   return __builtin_roundl(__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-round(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI double round(_A1 __x) _NOEXCEPT {
   return __builtin_round((double)__x);
 }
 
 // trunc
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI float trunc(float __x) _NOEXCEPT { return __builtin_trunc(__x); }
 
 template <class = int>
 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI double trunc(double __x) _NOEXCEPT {
   return __builtin_trunc(__x);
 }
 
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI long double trunc(long double __x) _NOEXCEPT {
   return __builtin_truncl(__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type
-trunc(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI double trunc(_A1 __x) _NOEXCEPT {
   return __builtin_trunc((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_ROUNDING_FUNCTIONS_H

libcxx/include/__math/traits.h

 
 // isinf
 
 template <class _A1, __enable_if_t<is_arithmetic<_A1>::value && numeric_limits<_A1>::has_infinity, int> = 0>
 _LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isinf(_A1 __x) _NOEXCEPT {
   return __builtin_isinf((typename __promote<_A1>::type)__x);
 }
 
-template <class _A1>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI
-    typename enable_if< is_arithmetic<_A1>::value && !numeric_limits<_A1>::has_infinity, bool>::type
-    isinf(_A1) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_arithmetic<_A1>::value && !numeric_limits<_A1>::has_infinity, int> = 0>
+_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isinf(_A1) _NOEXCEPT {
   return false;
 }
 
 #ifdef _LIBCPP_PREFERRED_OVERLOAD
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isinf(float __x) _NOEXCEPT {
   return __builtin_isinf(__x);
 }
 

libcxx/include/__math/trigonometric_functions.h

 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double cos(double __x) _NOEXCEPT {
   return __builtin_cos(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double cos(long double __x) _NOEXCEPT { return __builtin_cosl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type cos(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double cos(_A1 __x) _NOEXCEPT {
   return __builtin_cos((double)__x);
 }
 
 // sin
 
 inline _LIBCPP_HIDE_FROM_ABI float sin(float __x) _NOEXCEPT { return __builtin_sinf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double sin(double __x) _NOEXCEPT {
   return __builtin_sin(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double sin(long double __x) _NOEXCEPT { return __builtin_sinl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type sin(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double sin(_A1 __x) _NOEXCEPT {
   return __builtin_sin((double)__x);
 }
 
 // tan
 
 inline _LIBCPP_HIDE_FROM_ABI float tan(float __x) _NOEXCEPT { return __builtin_tanf(__x); }
 
 template <class = int>
 _LIBCPP_HIDE_FROM_ABI double tan(double __x) _NOEXCEPT {
   return __builtin_tan(__x);
 }
 
 inline _LIBCPP_HIDE_FROM_ABI long double tan(long double __x) _NOEXCEPT { return __builtin_tanl(__x); }
 
-template <class _A1>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<is_integral<_A1>::value, double>::type tan(_A1 __x) _NOEXCEPT {
+template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI double tan(_A1 __x) _NOEXCEPT {
   return __builtin_tan((double)__x);
 }
 
 } // namespace __math
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___MATH_TRIGONOMETRIC_FUNCTIONS_H