std::__is_fast_hash< _Hash > Struct Template Reference

#include <functional_hash.h>

Inheritance diagram for std::__is_fast_hash< _Hash >:

Public Types
typedef integral_constant< bool, __v >	type
typedef bool	value_type

Public Member Functions
constexpr	operator value_type () const noexcept
constexpr value_type	operator() () const noexcept

Static Public Attributes
static constexpr bool	value

Detailed Description

template<typename _Hash>
struct std::__is_fast_hash< _Hash >

Hint about performance of hash functions.

If a given hash function object is not fast, the hash-based containers will cache the hash code. The default behavior is to consider that hashers are fast unless specified otherwise.

Users can specialize this for their own hash functions in order to force caching of hash codes in unordered containers. Specializing this trait affects the ABI of the unordered containers, so use it carefully.

Definition at line 295 of file functional_hash.h.

Member Typedef Documentation

type

typedef integral_constant<bool, __v> std::integral_constant< bool, __v >::type

inherited

Definition at line 66 of file type_traits.

value_type

typedef bool std::integral_constant< bool, __v >::value_type

inherited

Definition at line 65 of file type_traits.

Member Function Documentation

operator value_type()

std::integral_constant< bool, __v >::operator value_type ( ) const

inlineconstexprnoexceptinherited

Definition at line 67 of file type_traits.

operator()()

value_type std::integral_constant< bool, __v >::operator() ( ) const

inlineconstexprnoexceptinherited

Definition at line 72 of file type_traits.

Member Data Documentation

value

bool std::integral_constant< bool, __v >::value

staticconstexprinherited

Definition at line 64 of file type_traits.

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The documentation for this struct was generated from the following file:

• functional_hash.h