Add new helper traits for signed/unsigned integer types

Reuse the __is_one_of alias in additional places, and define traits to
check for signed/unsigned integer types so we don't have to duplicate
those checks elsewhere.

The additional overloads for std::byte in <bit> were reviewed by LEWG
and considered undesirable, so this patch removes them.

	* include/bits/fs_path.h (path::__is_encoded_char): Use __is_one_of.
	* include/std/bit (_If_is_unsigned_integer_type): Remove.
	(_If_is_unsigned_integer): Use __is_unsigned_integer.
	(rotl(byte, unsigned), rotr(byte, unsigned), countl_zero(byte))
	(countl_one(byte), countr_zero(byte), countr_one(byte))
	(popcount(byte), ispow2(byte), ceil2(byte), floor2(byte))
	(log2p1(byte)): Remove.
	* include/std/charconv (__detail::__is_one_of): Move to <type_traits>.
	(__detail::__is_int_to_chars_type): Remove.
	(__detail::__integer_to_chars_result_type): Use __is_signed_integer
	and __is_unsigned_integer.
	* include/std/type_traits (__is_one_of): Move here from <charconv>.
	(__is_signed_integer, __is_unsigned_integer): New helpers.
	* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Remove test for
	std::byte overload.
	* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Likewise.
	* testsuite/26_numerics/bit/bitops.count/countl_one.cc: Likewise.
	* testsuite/26_numerics/bit/bitops.count/countl_zero.cc: Likewise.
	* testsuite/26_numerics/bit/bitops.count/countr_one.cc: Likewise.
	* testsuite/26_numerics/bit/bitops.count/countr_zero.cc: Likewise.
	* testsuite/26_numerics/bit/bitops.count/popcount.cc: Likewise.
	* testsuite/26_numerics/bit/bitops.rot/rotl.cc: Likewise.
	* testsuite/26_numerics/bit/bitops.rot/rotr.cc: Likewise.

From-SVN: r272695

1 files changed, 1 insertions, 59 deletions

diff --git a/libstdc++-v3/include/std/bit b/libstdc++-v3/include/std/bit
index e0c53e5..dd33dcf 100644
--- a/libstdc++-v3/include/std/bit
+++ b/libstdc++-v3/include/std/bit
@@ -222,19 +222,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 #if __cplusplus > 201703L
 
-  template<typename _Tp, typename _Up, bool = is_integral_v<_Tp>>
-    struct _If_is_unsigned_integer_type { };
-
-  template<typename _Up>
-    struct _If_is_unsigned_integer_type<bool, _Up, true> { };
-
-  template<typename _Tp, typename _Up>
-    struct _If_is_unsigned_integer_type<_Tp, _Up, true>
-    : enable_if<is_same_v<_Tp, make_unsigned_t<_Tp>>, _Up> { };
-
   template<typename _Tp, typename _Up = _Tp>
     using _If_is_unsigned_integer
-      = typename _If_is_unsigned_integer_type<remove_cv_t<_Tp>, _Up>::type;
+      = enable_if_t<__is_unsigned_integer<_Tp>::value, _Up>;
 
 #if ! __STRICT_ANSI__
   // [bitops.rot], rotating
@@ -299,54 +289,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     log2p1(_Tp __x) noexcept
     { return std::__log2p1(__x); }
 
-#if ! __STRICT_ANSI__
-  enum class byte : unsigned char;
-
-  constexpr byte
-  rotl(byte __x, unsigned int __s) noexcept
-  { return (byte)std::__rotl((unsigned char)__x, __s); }
-
-  constexpr byte
-  rotr(byte __x, unsigned int __s) noexcept
-  { return (byte)std::__rotr((unsigned char)__x, __s); }
-
-  constexpr int
-  countl_zero(byte __x) noexcept
-  { return std::__countl_zero((unsigned char)__x); }
-
-  constexpr int
-  countl_one(byte __x) noexcept
-  { return std::__countl_one((unsigned char)__x); }
-
-  constexpr int
-  countr_zero(byte __x) noexcept
-  { return std::__countr_zero((unsigned char)__x); }
-
-  constexpr int
-  countr_one(byte __x) noexcept
-  { return std::__countr_one((unsigned char)__x); }
-
-  constexpr int
-  popcount(byte __x) noexcept
-  { return std::__popcount((unsigned char)__x); }
-
-  constexpr bool
-  ispow2(byte __x) noexcept
-  { return std::__ispow2((unsigned char)__x); }
-
-  constexpr byte
-  ceil2(byte __x) noexcept
-  { return (byte)std::__ceil2((unsigned char)__x); }
-
-  constexpr byte
-  floor2(byte __x) noexcept
-  { return (byte)std::__floor2((unsigned char)__x); }
-
-  constexpr byte
-  log2p1(byte __x) noexcept
-  { return (byte)std::__log2p1((unsigned char)__x); }
-#endif
-
 #endif // C++2a
 
 _GLIBCXX_END_NAMESPACE_VERSION