libstdc++: Replace __int_limits with __numeric_traits_integer

I recently added std::__detail::__int_limits as a lightweight
alternative to std::numeric_limits, forgetting that the values it
provides (digits, min and max) are already provided by
__gnu_cxx::__numeric_traits.

This change adds __int_traits as an alias for __numeric_traits_integer.
This avoids instantiating __numeric_traits to decide whether to use
__numeric_traits_integer or __numeric_traits_floating. Then all uses of
__int_limits can be replaced with __int_traits, and __int_limits can be
removed.

libstdc++-v3/ChangeLog:

	* include/Makefile.am: Remove bits/int_limits.h.
	* include/Makefile.in: Regenerate.
	* include/bits/int_limits.h: Removed.
	* include/bits/parse_numbers.h (_Select_int_base): Replace
	__int_limits with __int_traits.
	* include/bits/range_access.h (_SSize::operator()): Likewise.
	* include/ext/numeric_traits.h (__numeric_traits_integer): Add
	static assertion.
	(__int_traits): New alias template.
	* include/std/bit (__rotl, __rotr, __countl_zero, __countl_one)
	(__countr_zero, __countr_one, __popcount, __bit_ceil)
	(__bit_floor, __bit_width) Replace __int_limits with
	__int_traits.
	* include/std/charconv (__to_chars_8, __from_chars_binary)
	(__from_chars_alpha_to_num, from_chars): Likewise.
	* include/std/memory_resource (polymorphic_allocator::allocate)
	(polymorphic_allocator::allocate_object): Likewise.
	* include/std/string_view (basic_string_view::_S_compare):
	Likewise.
	* include/std/utility (cmp_equal, cmp_less, in_range): Likewise.

11 files changed, 67 insertions, 133 deletions

diff --git a/libstdc++-v3/include/Makefile.am b/libstdc++-v3/include/Makefile.am
index 80aeb3f..e131ce0 100644
--- a/libstdc++-v3/include/Makefile.am
+++ b/libstdc++-v3/include/Makefile.am
@@ -129,7 +129,6 @@ bits_headers = \
 	${bits_srcdir}/hashtable.h \
 	${bits_srcdir}/hashtable_policy.h \
 	${bits_srcdir}/indirect_array.h \
-	${bits_srcdir}/int_limits.h \
 	${bits_srcdir}/invoke.h \
 	${bits_srcdir}/ios_base.h \
 	${bits_srcdir}/istream.tcc \
diff --git a/libstdc++-v3/include/Makefile.in b/libstdc++-v3/include/Makefile.in
index 269645e..c0b71e1 100644
--- a/libstdc++-v3/include/Makefile.in
+++ b/libstdc++-v3/include/Makefile.in
@@ -475,7 +475,6 @@ bits_headers = \
 	${bits_srcdir}/hashtable.h \
 	${bits_srcdir}/hashtable_policy.h \
 	${bits_srcdir}/indirect_array.h \
-	${bits_srcdir}/int_limits.h \
 	${bits_srcdir}/invoke.h \
 	${bits_srcdir}/ios_base.h \
 	${bits_srcdir}/istream.tcc \
diff --git a/libstdc++-v3/include/bits/int_limits.h b/libstdc++-v3/include/bits/int_limits.h
deleted file mode 100644
index 7ae3437..0000000
--- a/libstdc++-v3/include/bits/int_limits.h
+++ /dev/null
@@ -1,74 +0,0 @@
-// Minimal replacement for numeric_limits of integers. -*- C++ -*-
-
-// Copyright (C) 2020 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// Under Section 7 of GPL version 3, you are granted additional
-// permissions described in the GCC Runtime Library Exception, version
-// 3.1, as published by the Free Software Foundation.
-
-// You should have received a copy of the GNU General Public License and
-// a copy of the GCC Runtime Library Exception along with this program;
-// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
-// <http://www.gnu.org/licenses/>.
-
-/** @file bits/int_limits.h
- *  This is an internal header file, included by other library headers.
- *  Do not attempt to use it directly. @headername{limits}
- */
-
-#ifndef _GLIBCXX_INT_LIMITS_H
-#define _GLIBCXX_INT_LIMITS_H 1
-
-#pragma GCC system_header
-
-#if __cplusplus >= 201103L
-#include <bits/c++config.h>
-
-namespace std _GLIBCXX_VISIBILITY(default)
-{
-_GLIBCXX_BEGIN_NAMESPACE_VERSION
-namespace __detail
-{
-  // This template is used for arbitrary signed and unsigned integer types
-  // (by headers <bit> and <charconv>) and for specific integer types
-  // (by <memory_resource> and <string_view>) but also for char (<charconv>).
-  // For simplicity's sake, all integral types except bool are supported.
-
-  // Lightweight alternative to numeric_limits<signed integer type>.
-  template<typename _Tp, bool = is_signed<_Tp>::value>
-    struct __int_limits
-    {
-      static_assert(is_integral<_Tp>::value, "unsupported specialization");
-      using _Up = typename make_unsigned<_Tp>::type;
-      static constexpr int digits = sizeof(_Tp) * __CHAR_BIT__ - 1;
-      static constexpr _Tp min() noexcept { return _Tp(_Up(1) << digits); }
-      static constexpr _Tp max() noexcept { return _Tp(_Up(~_Up(0)) >> 1); }
-    };
-
-  // Lightweight alternative to numeric_limits<unsigned integer type>.
-  template<typename _Tp>
-    struct __int_limits<_Tp, false>
-    {
-      static_assert(is_integral<_Tp>::value, "unsupported specialization");
-      static constexpr int digits = sizeof(_Tp) * __CHAR_BIT__;
-      static constexpr _Tp min() noexcept { return 0; }
-      static constexpr _Tp max() noexcept { return _Tp(-1); }
-    };
-
-  template<> struct __int_limits<bool>; // not defined
-}
-_GLIBCXX_END_NAMESPACE_VERSION
-} // namespace
-#endif // C++11
-#endif // _GLIBCXX_INT_LIMITS_H
diff --git a/libstdc++-v3/include/bits/parse_numbers.h b/libstdc++-v3/include/bits/parse_numbers.h
index 6a75d00..5e80907 100644
--- a/libstdc++-v3/include/bits/parse_numbers.h
+++ b/libstdc++-v3/include/bits/parse_numbers.h
@@ -36,7 +36,7 @@
 
 #if __cplusplus >= 201402L
 
-#include <bits/int_limits.h>
+#include <ext/numeric_traits.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
@@ -265,7 +265,7 @@ namespace __select_int
 
   template<unsigned long long _Val, typename _IntType, typename... _Ints>
     struct _Select_int_base<_Val, _IntType, _Ints...>
-    : conditional_t<(_Val <= __detail::__int_limits<_IntType>::max()),
+    : conditional_t<(_Val <= __gnu_cxx::__int_traits<_IntType>::__max),
 		    integral_constant<_IntType, _Val>,
 		    _Select_int_base<_Val, _Ints...>>
     { };
diff --git a/libstdc++-v3/include/bits/range_access.h b/libstdc++-v3/include/bits/range_access.h
index 82d9e21..3919183 100644
--- a/libstdc++-v3/include/bits/range_access.h
+++ b/libstdc++-v3/include/bits/range_access.h
@@ -35,7 +35,7 @@
 #if __cplusplus >= 201103L
 #include <initializer_list>
 #include <bits/iterator_concepts.h>
-#include <bits/int_limits.h>
+#include <ext/numeric_traits.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
@@ -727,12 +727,12 @@ namespace ranges
 	{
 	  using __iter_type = decltype(_Begin{}(std::forward<_Tp>(__e)));
 	  using __diff_type = iter_difference_t<__iter_type>;
-	  using std::__detail::__int_limits;
+	  using __gnu_cxx::__int_traits;
 	  auto __size = _Size{}(std::forward<_Tp>(__e));
 	  if constexpr (integral<__diff_type>)
 	    {
-	      if constexpr (__int_limits<__diff_type>::digits
-			    < __int_limits<ptrdiff_t>::digits)
+	      if constexpr (__int_traits<__diff_type>::__digits
+			    < __int_traits<ptrdiff_t>::__digits)
 		return static_cast<ptrdiff_t>(__size);
 	    }
 	  return static_cast<__diff_type>(__size);
diff --git a/libstdc++-v3/include/ext/numeric_traits.h b/libstdc++-v3/include/ext/numeric_traits.h
index 4c74d7e..69f286d 100644
--- a/libstdc++-v3/include/ext/numeric_traits.h
+++ b/libstdc++-v3/include/ext/numeric_traits.h
@@ -54,6 +54,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Value>
     struct __numeric_traits_integer
     {
+#if __cplusplus >= 201103L
+      static_assert(std::__is_integer<_Value>::__value,
+		    "invalid specialization");
+#endif
+
       // Only integers for initialization of member constant.
       static const _Value __min = __glibcxx_min(_Value);
       static const _Value __max = __glibcxx_max(_Value);
@@ -76,6 +81,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Value>
     const int __numeric_traits_integer<_Value>::__digits;
 
+#if __cplusplus >= 201103L
+  template<typename _Tp>
+    using __int_traits = __numeric_traits_integer<_Tp>;
+#endif
+
 #undef __glibcxx_signed
 #undef __glibcxx_digits
 #undef __glibcxx_min
diff --git a/libstdc++-v3/include/std/bit b/libstdc++-v3/include/std/bit
index 69e9554..f434482 100644
--- a/libstdc++-v3/include/std/bit
+++ b/libstdc++-v3/include/std/bit
@@ -34,7 +34,7 @@
 #if __cplusplus >= 201402L
 
 #include <type_traits>
-#include <bits/int_limits.h>
+#include <ext/numeric_traits.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
@@ -55,7 +55,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr _Tp
     __rotl(_Tp __x, int __s) noexcept
     {
-      constexpr auto _Nd = __detail::__int_limits<_Tp>::digits;
+      constexpr auto _Nd = __gnu_cxx::__int_traits<_Tp>::__digits;
       const int __r = __s % _Nd;
       if (__r == 0)
 	return __x;
@@ -69,7 +69,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr _Tp
     __rotr(_Tp __x, int __s) noexcept
     {
-      constexpr auto _Nd = __detail::__int_limits<_Tp>::digits;
+      constexpr auto _Nd = __gnu_cxx::__int_traits<_Tp>::__digits;
       const int __r = __s % _Nd;
       if (__r == 0)
 	return __x;
@@ -83,15 +83,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr int
     __countl_zero(_Tp __x) noexcept
     {
-      using std::__detail::__int_limits;
-      constexpr auto _Nd = __int_limits<_Tp>::digits;
+      using __gnu_cxx::__int_traits;
+      constexpr auto _Nd = __int_traits<_Tp>::__digits;
 
       if (__x == 0)
         return _Nd;
 
-      constexpr auto _Nd_ull = __int_limits<unsigned long long>::digits;
-      constexpr auto _Nd_ul = __int_limits<unsigned long>::digits;
-      constexpr auto _Nd_u = __int_limits<unsigned>::digits;
+      constexpr auto _Nd_ull = __int_traits<unsigned long long>::__digits;
+      constexpr auto _Nd_ul = __int_traits<unsigned long>::__digits;
+      constexpr auto _Nd_u = __int_traits<unsigned>::__digits;
 
       if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u)
 	{
@@ -119,7 +119,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	      constexpr int __diff = (2 * _Nd_ull) - _Nd;
 	      return __builtin_clzll(__high) - __diff;
 	    }
-	  constexpr auto __max_ull = __int_limits<unsigned long long>::max();
+	  constexpr auto __max_ull = __int_traits<unsigned long long>::__max;
 	  unsigned long long __low = __x & __max_ull;
 	  return (_Nd - _Nd_ull) + __builtin_clzll(__low);
 	}
@@ -129,8 +129,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr int
     __countl_one(_Tp __x) noexcept
     {
-      if (__x == __detail::__int_limits<_Tp>::max())
-	return __detail::__int_limits<_Tp>::digits;
+      if (__x == __gnu_cxx::__int_traits<_Tp>::__max)
+	return __gnu_cxx::__int_traits<_Tp>::__digits;
       return std::__countl_zero<_Tp>((_Tp)~__x);
     }
 
@@ -138,15 +138,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr int
     __countr_zero(_Tp __x) noexcept
     {
-      using std::__detail::__int_limits;
-      constexpr auto _Nd = __int_limits<_Tp>::digits;
+      using __gnu_cxx::__int_traits;
+      constexpr auto _Nd = __int_traits<_Tp>::__digits;
 
       if (__x == 0)
         return _Nd;
 
-      constexpr auto _Nd_ull = __int_limits<unsigned long long>::digits;
-      constexpr auto _Nd_ul = __int_limits<unsigned long>::digits;
-      constexpr auto _Nd_u = __int_limits<unsigned>::digits;
+      constexpr auto _Nd_ull = __int_traits<unsigned long long>::__digits;
+      constexpr auto _Nd_ul = __int_traits<unsigned long>::__digits;
+      constexpr auto _Nd_u = __int_traits<unsigned>::__digits;
 
       if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u)
 	return __builtin_ctz(__x);
@@ -159,7 +159,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  static_assert(_Nd <= (2 * _Nd_ull),
 			"Maximum supported integer size is 128-bit");
 
-	  constexpr auto __max_ull = __int_limits<unsigned long long>::max();
+	  constexpr auto __max_ull = __int_traits<unsigned long long>::__max;
 	  unsigned long long __low = __x & __max_ull;
 	  if (__low != 0)
 	    return __builtin_ctzll(__low);
@@ -172,8 +172,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr int
     __countr_one(_Tp __x) noexcept
     {
-      if (__x == __detail::__int_limits<_Tp>::max())
-	return __detail::__int_limits<_Tp>::digits;
+      if (__x == __gnu_cxx::__int_traits<_Tp>::__max)
+	return __gnu_cxx::__int_traits<_Tp>::__digits;
       return std::__countr_zero((_Tp)~__x);
     }
 
@@ -181,15 +181,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr int
     __popcount(_Tp __x) noexcept
     {
-      using std::__detail::__int_limits;
-      constexpr auto _Nd = __int_limits<_Tp>::digits;
+      using __gnu_cxx::__int_traits;
+      constexpr auto _Nd = __int_traits<_Tp>::__digits;
 
       if (__x == 0)
         return 0;
 
-      constexpr auto _Nd_ull = __int_limits<unsigned long long>::digits;
-      constexpr auto _Nd_ul = __int_limits<unsigned long>::digits;
-      constexpr auto _Nd_u = __int_limits<unsigned>::digits;
+      constexpr auto _Nd_ull = __int_traits<unsigned long long>::__digits;
+      constexpr auto _Nd_ul = __int_traits<unsigned long>::__digits;
+      constexpr auto _Nd_u = __int_traits<unsigned>::__digits;
 
       if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u)
 	return __builtin_popcount(__x);
@@ -202,7 +202,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  static_assert(_Nd <= (2 * _Nd_ull),
 			"Maximum supported integer size is 128-bit");
 
-	  constexpr auto __max_ull = __int_limits<unsigned long long>::max();
+	  constexpr auto __max_ull = __int_traits<unsigned long long>::__max;
 	  unsigned long long __low = __x & __max_ull;
 	  unsigned long long __high = __x >> _Nd_ull;
 	  return __builtin_popcountll(__low) + __builtin_popcountll(__high);
@@ -218,8 +218,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr _Tp
     __bit_ceil(_Tp __x) noexcept
     {
-      using std::__detail::__int_limits;
-      constexpr auto _Nd = __int_limits<_Tp>::digits;
+      using __gnu_cxx::__int_traits;
+      constexpr auto _Nd = __int_traits<_Tp>::__digits;
       if (__x == 0 || __x == 1)
         return 1;
       auto __shift_exponent = _Nd - std::__countl_zero((_Tp)(__x - 1u));
@@ -230,7 +230,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
       if (!__builtin_is_constant_evaluated())
 	{
-	  __glibcxx_assert( __shift_exponent != __int_limits<_Tp>::digits );
+	  __glibcxx_assert( __shift_exponent != __int_traits<_Tp>::__digits );
 	}
 #endif
       using __promoted_type = decltype(__x << 1);
@@ -251,7 +251,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr _Tp
     __bit_floor(_Tp __x) noexcept
     {
-      constexpr auto _Nd = __detail::__int_limits<_Tp>::digits;
+      constexpr auto _Nd = __gnu_cxx::__int_traits<_Tp>::__digits;
       if (__x == 0)
         return 0;
       return (_Tp)1u << (_Nd - std::__countl_zero((_Tp)(__x >> 1)));
@@ -261,7 +261,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     constexpr _Tp
     __bit_width(_Tp __x) noexcept
     {
-      constexpr auto _Nd = __detail::__int_limits<_Tp>::digits;
+      constexpr auto _Nd = __gnu_cxx::__int_traits<_Tp>::__digits;
       return _Nd - std::__countl_zero(__x);
     }
 
diff --git a/libstdc++-v3/include/std/charconv b/libstdc++-v3/include/std/charconv
index b725e5d2..cc7dd0e 100644
--- a/libstdc++-v3/include/std/charconv
+++ b/libstdc++-v3/include/std/charconv
@@ -42,7 +42,7 @@
 #include <cctype>		// for isdigit
 #include <bits/charconv.h>	// for __to_chars_len, __to_chars_10_impl
 #include <bits/error_constants.h> // for std::errc
-#include <bits/int_limits.h>
+#include <ext/numeric_traits.h>
 
 // FIXME: Define when floating point is supported:
 // #define __cpp_lib_to_chars 201611L
@@ -237,7 +237,7 @@ namespace __detail
       to_chars_result __res;
       unsigned __len;
 
-      if _GLIBCXX17_CONSTEXPR (__detail::__int_limits<_Tp>::digits <= 16)
+      if _GLIBCXX17_CONSTEXPR (__gnu_cxx::__int_traits<_Tp>::__digits <= 16)
 	{
 	  __len = __val > 077777u ? 6u
 	    : __val > 07777u ? 5u
@@ -432,7 +432,7 @@ namespace __detail
 	  __i++;
 	}
       __first += __i;
-      return (__i - __leading_zeroes) <= __detail::__int_limits<_Tp>::digits;
+      return (__i - __leading_zeroes) <= __gnu_cxx::__int_traits<_Tp>::__digits;
     }
 
   /// std::from_chars implementation for integers in bases 3 to 10.
@@ -551,7 +551,7 @@ namespace __detail
     case 'Z':
       return 35;
     }
-    return __detail::__int_limits<unsigned char>::max();
+    return __gnu_cxx::__int_traits<unsigned char>::__max;
   }
 
   /// std::from_chars implementation for integers in bases 11 to 26.
@@ -638,10 +638,10 @@ namespace __detail
 		}
 	      else
 		{
-		  if _GLIBCXX17_CONSTEXPR (__detail::__int_limits<_Up>::max()
-		      > __detail::__int_limits<_Tp>::max())
+		  if _GLIBCXX17_CONSTEXPR (__gnu_cxx::__int_traits<_Up>::__max
+		      > __gnu_cxx::__int_traits<_Tp>::__max)
 		    {
-		      if (__val > __detail::__int_limits<_Tp>::max())
+		      if (__val > __gnu_cxx::__int_traits<_Tp>::__max)
 			__res.ec = errc::result_out_of_range;
 		      else
 			__value = __val;
diff --git a/libstdc++-v3/include/std/memory_resource b/libstdc++-v3/include/std/memory_resource
index 514c988..2b8735b 100644
--- a/libstdc++-v3/include/std/memory_resource
+++ b/libstdc++-v3/include/std/memory_resource
@@ -39,7 +39,7 @@
 #include <cstddef>			// size_t, max_align_t, byte
 #include <shared_mutex>			// shared_mutex
 #include <bits/functexcept.h>
-#include <bits/int_limits.h>
+#include <ext/numeric_traits.h>
 #include <debug/assertions.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
@@ -168,7 +168,7 @@ namespace pmr
       allocate(size_t __n)
       __attribute__((__returns_nonnull__))
       {
-	if (__n > (__detail::__int_limits<size_t>::max() / sizeof(_Tp)))
+	if (__n > (__gnu_cxx::__int_traits<size_t>::__max / sizeof(_Tp)))
 	  _GLIBCXX_THROW_OR_ABORT(bad_array_new_length());
 	return static_cast<_Tp*>(_M_resource->allocate(__n * sizeof(_Tp),
 						       alignof(_Tp)));
@@ -194,7 +194,7 @@ namespace pmr
 	[[nodiscard]] _Up*
 	allocate_object(size_t __n = 1)
 	{
-	  if ((__detail::__int_limits<size_t>::max() / sizeof(_Up)) < __n)
+	  if ((__gnu_cxx::__int_traits<size_t>::__max / sizeof(_Up)) < __n)
 	    _GLIBCXX_THROW_OR_ABORT(bad_array_new_length());
 	  return static_cast<_Up*>(allocate_bytes(__n * sizeof(_Up),
 						  alignof(_Up)));
diff --git a/libstdc++-v3/include/std/string_view b/libstdc++-v3/include/std/string_view
index 7c7c1b3..ca0d6265 100644
--- a/libstdc++-v3/include/std/string_view
+++ b/libstdc++-v3/include/std/string_view
@@ -40,9 +40,9 @@
 #include <iosfwd>
 #include <bits/char_traits.h>
 #include <bits/functional_hash.h>
-#include <bits/int_limits.h>
 #include <bits/range_access.h>
 #include <bits/ostream_insert.h>
+#include <ext/numeric_traits.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
@@ -462,10 +462,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _S_compare(size_type __n1, size_type __n2) noexcept
       {
 	const difference_type __diff = __n1 - __n2;
-	if (__diff > __detail::__int_limits<int>::max())
-	  return __detail::__int_limits<int>::max();
-	if (__diff < __detail::__int_limits<int>::min())
-	  return __detail::__int_limits<int>::min();
+	if (__diff > __gnu_cxx::__int_traits<int>::__max)
+	  return __gnu_cxx::__int_traits<int>::__max;
+	if (__diff < __gnu_cxx::__int_traits<int>::__min)
+	  return __gnu_cxx::__int_traits<int>::__min;
 	return static_cast<int>(__diff);
       }
 
diff --git a/libstdc++-v3/include/std/utility b/libstdc++-v3/include/std/utility
index cde3752..4a9ad60 100644
--- a/libstdc++-v3/include/std/utility
+++ b/libstdc++-v3/include/std/utility
@@ -76,7 +76,7 @@
 #include <initializer_list>
 
 #if __cplusplus > 201703L
-#include <bits/int_limits.h>
+#include <ext/numeric_traits.h>
 #endif
 
 namespace std _GLIBCXX_VISIBILITY(default)
@@ -456,16 +456,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       static_assert(__is_standard_integer<_Up>::value);
       static_assert(__is_standard_integer<_Tp>::value);
-      using std::__detail::__int_limits;
+      using __gnu_cxx::__int_traits;
 
       if constexpr (is_signed_v<_Tp> == is_signed_v<_Up>)
-	return __int_limits<_Up>::min() <= __t
-	  && __t <= __int_limits<_Up>::max();
+	return __int_traits<_Up>::__min <= __t
+	  && __t <= __int_traits<_Up>::__max;
       else if constexpr (is_signed_v<_Tp>)
 	return __t >= 0
-	  && make_unsigned_t<_Tp>(__t) <= __int_limits<_Up>::max();
+	  && make_unsigned_t<_Tp>(__t) <= __int_traits<_Up>::__max;
       else
-	return __t <= make_unsigned_t<_Up>(__int_limits<_Up>::max());
+	return __t <= make_unsigned_t<_Up>(__int_traits<_Up>::__max);
     }
 #endif // C++20
 #endif // C++17