Implement P0513R0 - "Poisoning the Hash"
Summary: Exactly what the title says. This patch also adds a `std::hash<nullptr_t>` specialization in C++17, but it was not added by this paper and I can't find the actual paper that adds it. See http://wg21.link/P0513R0 for more info. If there are no comments in the next couple of days I'll commit this Reviewers: mclow.lists, K-ballo, EricWF Reviewed By: EricWF Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D28938 git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292684 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Fiselier
@@ -485,6 +485,7 @@ POLICY: For non-variadic implementations, the number of arguments is limited
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#include <exception>
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#include <memory>
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#include <tuple>
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#include <utility>
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#include <__functional_base>
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@@ -2339,247 +2340,6 @@ bind(_Fp&& __f, _BoundArgs&&... __bound_args)
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#endif // _LIBCPP_HAS_NO_VARIADICS
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<bool>
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: public unary_function<bool, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(bool __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<char>
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: public unary_function<char, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<signed char>
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: public unary_function<signed char, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(signed char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<unsigned char>
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: public unary_function<unsigned char, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(unsigned char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<char16_t>
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: public unary_function<char16_t, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(char16_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<char32_t>
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: public unary_function<char32_t, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(char32_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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#endif // _LIBCPP_HAS_NO_UNICODE_CHARS
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<wchar_t>
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: public unary_function<wchar_t, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(wchar_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<short>
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: public unary_function<short, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<unsigned short>
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: public unary_function<unsigned short, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(unsigned short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<int>
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: public unary_function<int, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<unsigned int>
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: public unary_function<unsigned int, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(unsigned int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<long>
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: public unary_function<long, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<unsigned long>
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: public unary_function<unsigned long, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(unsigned long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<long long>
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: public __scalar_hash<long long>
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{
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<unsigned long long>
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: public __scalar_hash<unsigned long long>
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{
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};
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#ifndef _LIBCPP_HAS_NO_INT128
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<__int128_t>
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: public __scalar_hash<__int128_t>
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{
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<__uint128_t>
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: public __scalar_hash<__uint128_t>
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{
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};
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#endif
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<float>
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: public __scalar_hash<float>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(float __v) const _NOEXCEPT
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{
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// -0.0 and 0.0 should return same hash
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if (__v == 0)
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return 0;
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return __scalar_hash<float>::operator()(__v);
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}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<double>
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: public __scalar_hash<double>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(double __v) const _NOEXCEPT
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{
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// -0.0 and 0.0 should return same hash
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if (__v == 0)
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return 0;
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return __scalar_hash<double>::operator()(__v);
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}
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};
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<long double>
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: public __scalar_hash<long double>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(long double __v) const _NOEXCEPT
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{
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// -0.0 and 0.0 should return same hash
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if (__v == 0)
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return 0;
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#if defined(__i386__)
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// Zero out padding bits
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union
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{
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long double __t;
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struct
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{
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size_t __a;
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size_t __b;
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size_t __c;
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size_t __d;
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} __s;
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} __u;
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__u.__s.__a = 0;
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__u.__s.__b = 0;
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__u.__s.__c = 0;
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__u.__s.__d = 0;
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__u.__t = __v;
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return __u.__s.__a ^ __u.__s.__b ^ __u.__s.__c ^ __u.__s.__d;
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#elif defined(__x86_64__)
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// Zero out padding bits
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union
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{
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long double __t;
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struct
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{
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size_t __a;
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size_t __b;
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} __s;
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} __u;
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__u.__s.__a = 0;
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__u.__s.__b = 0;
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__u.__t = __v;
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return __u.__s.__a ^ __u.__s.__b;
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#else
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return __scalar_hash<long double>::operator()(__v);
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#endif
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}
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};
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#if _LIBCPP_STD_VER > 11
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template <class _Tp, bool = is_enum<_Tp>::value>
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struct _LIBCPP_TEMPLATE_VIS __enum_hash
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: public unary_function<_Tp, size_t>
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{
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_LIBCPP_INLINE_VISIBILITY
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size_t operator()(_Tp __v) const _NOEXCEPT
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{
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typedef typename underlying_type<_Tp>::type type;
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return hash<type>{}(static_cast<type>(__v));
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}
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};
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template <class _Tp>
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struct _LIBCPP_TEMPLATE_VIS __enum_hash<_Tp, false> {
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__enum_hash() = delete;
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__enum_hash(__enum_hash const&) = delete;
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__enum_hash& operator=(__enum_hash const&) = delete;
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};
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template <class _Tp>
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struct _LIBCPP_TEMPLATE_VIS hash : public __enum_hash<_Tp>
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{
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};
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#endif
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#if _LIBCPP_STD_VER > 14
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#define __cpp_lib_invoke 201411
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