[libcxx-commits] [libcxx] cccf1ef - [libc++] Remove cycle between <type_traits> and <cstddef>
Eric Fiselier via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Feb 14 08:37:04 PST 2020
Author: Eric Fiselier
Date: 2020-02-14T17:36:27+01:00
New Revision: cccf1ef0c89432339363fc0121e3d97f5a04ac69
URL: https://github.com/llvm/llvm-project/commit/cccf1ef0c89432339363fc0121e3d97f5a04ac69
DIFF: https://github.com/llvm/llvm-project/commit/cccf1ef0c89432339363fc0121e3d97f5a04ac69.diff
LOG: [libc++] Remove cycle between <type_traits> and <cstddef>
This was caused by byte depending on traits. This patch moves
the minimal amount of meta-programming into <cstddef> to break the cycle.
Added:
Modified:
libcxx/include/cstddef
libcxx/include/type_traits
Removed:
################################################################################
diff --git a/libcxx/include/cstddef b/libcxx/include/cstddef
index bd62d6db39e8..87eee4bf5b42 100644
--- a/libcxx/include/cstddef
+++ b/libcxx/include/cstddef
@@ -57,6 +57,32 @@ using ::max_align_t;
typedef long double max_align_t;
#endif
+template <class _Tp> struct __libcpp_is_integral { enum { value = 0 }; };
+template <> struct __libcpp_is_integral<bool> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<char> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<signed char> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<unsigned char> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<wchar_t> { enum { value = 1 }; };
+#ifndef _LIBCPP_NO_HAS_CHAR8_T
+template <> struct __libcpp_is_integral<char8_t> { enum { value = 1 }; };
+#endif
+#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
+template <> struct __libcpp_is_integral<char16_t> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<char32_t> { enum { value = 1 }; };
+#endif // _LIBCPP_HAS_NO_UNICODE_CHARS
+template <> struct __libcpp_is_integral<short> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<unsigned short> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<int> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<unsigned int> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<long> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<unsigned long> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<long long> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<unsigned long long> { enum { value = 1 }; };
+#ifndef _LIBCPP_HAS_NO_INT128
+template <> struct __libcpp_is_integral<__int128_t> { enum { value = 1 }; };
+template <> struct __libcpp_is_integral<__uint128_t> { enum { value = 1 }; };
+#endif
+
_LIBCPP_END_NAMESPACE_STD
#if _LIBCPP_STD_VER > 14
@@ -64,6 +90,11 @@ namespace std // purposefully not versioned
{
enum class byte : unsigned char {};
+
+template <bool> struct __enable_if_integral_imp {};
+template <> struct __enable_if_integral_imp<true> { using type = byte; };
+template <class _Tp> using _EnableByteOverload = typename __enable_if_integral_imp<__libcpp_is_integral<_Tp>::value>::type;
+
constexpr byte operator| (byte __lhs, byte __rhs) noexcept
{
return static_cast<byte>(
@@ -104,10 +135,31 @@ constexpr byte operator~ (byte __b) noexcept
~static_cast<unsigned int>(__b)
));
}
-
+template <class _Integer>
+ constexpr _EnableByteOverload<_Integer> &
+ operator<<=(byte& __lhs, _Integer __shift) noexcept
+ { return __lhs = __lhs << __shift; }
+
+template <class _Integer>
+ constexpr _EnableByteOverload<_Integer>
+ operator<< (byte __lhs, _Integer __shift) noexcept
+ { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) << __shift)); }
+
+template <class _Integer>
+ constexpr _EnableByteOverload<_Integer> &
+ operator>>=(byte& __lhs, _Integer __shift) noexcept
+ { return __lhs = __lhs >> __shift; }
+
+template <class _Integer>
+ constexpr _EnableByteOverload<_Integer>
+ operator>> (byte __lhs, _Integer __shift) noexcept
+ { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) >> __shift)); }
+
+template <class _Integer, class = _EnableByteOverload<_Integer> >
+ constexpr _Integer
+ to_integer(byte __b) noexcept { return static_cast<_Integer>(__b); }
}
-#include <type_traits> // rest of byte
#endif
#endif // _LIBCPP_CSTDDEF
diff --git a/libcxx/include/type_traits b/libcxx/include/type_traits
index f8ee5648d358..6b8b855afc65 100644
--- a/libcxx/include/type_traits
+++ b/libcxx/include/type_traits
@@ -735,34 +735,8 @@ _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_null_pointer_v
// is_integral
-template <class _Tp> struct __libcpp_is_integral : public false_type {};
-template <> struct __libcpp_is_integral<bool> : public true_type {};
-template <> struct __libcpp_is_integral<char> : public true_type {};
-template <> struct __libcpp_is_integral<signed char> : public true_type {};
-template <> struct __libcpp_is_integral<unsigned char> : public true_type {};
-template <> struct __libcpp_is_integral<wchar_t> : public true_type {};
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-template <> struct __libcpp_is_integral<char8_t> : public true_type {};
-#endif
-#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
-template <> struct __libcpp_is_integral<char16_t> : public true_type {};
-template <> struct __libcpp_is_integral<char32_t> : public true_type {};
-#endif // _LIBCPP_HAS_NO_UNICODE_CHARS
-template <> struct __libcpp_is_integral<short> : public true_type {};
-template <> struct __libcpp_is_integral<unsigned short> : public true_type {};
-template <> struct __libcpp_is_integral<int> : public true_type {};
-template <> struct __libcpp_is_integral<unsigned int> : public true_type {};
-template <> struct __libcpp_is_integral<long> : public true_type {};
-template <> struct __libcpp_is_integral<unsigned long> : public true_type {};
-template <> struct __libcpp_is_integral<long long> : public true_type {};
-template <> struct __libcpp_is_integral<unsigned long long> : public true_type {};
-#ifndef _LIBCPP_HAS_NO_INT128
-template <> struct __libcpp_is_integral<__int128_t> : public true_type {};
-template <> struct __libcpp_is_integral<__uint128_t> : public true_type {};
-#endif
-
template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_integral
- : public __libcpp_is_integral<typename remove_cv<_Tp>::type> {};
+ : public _BoolConstant<__libcpp_is_integral<typename remove_cv<_Tp>::type>::value> {};
#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
template <class _Tp>
@@ -4046,29 +4020,7 @@ _LIBCPP_END_NAMESPACE_STD
// std::byte
namespace std // purposefully not versioned
{
-template <class _Integer>
- constexpr typename enable_if<is_integral_v<_Integer>, byte>::type &
- operator<<=(byte& __lhs, _Integer __shift) noexcept
- { return __lhs = __lhs << __shift; }
-
-template <class _Integer>
- constexpr typename enable_if<is_integral_v<_Integer>, byte>::type
- operator<< (byte __lhs, _Integer __shift) noexcept
- { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) << __shift)); }
-
-template <class _Integer>
- constexpr typename enable_if<is_integral_v<_Integer>, byte>::type &
- operator>>=(byte& __lhs, _Integer __shift) noexcept
- { return __lhs = __lhs >> __shift; }
-
-template <class _Integer>
- constexpr typename enable_if<is_integral_v<_Integer>, byte>::type
- operator>> (byte __lhs, _Integer __shift) noexcept
- { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) >> __shift)); }
-
-template <class _Integer>
- constexpr typename enable_if<is_integral_v<_Integer>, _Integer>::type
- to_integer(byte __b) noexcept { return static_cast<_Integer>(__b); }
+
}
#endif
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