NAME

       std::__is_fast_hash< _Hash >

SYNOPSIS

       #include <functional>

       Inherits std::integral_constant< _Tp, __v >.

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

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

   Static Public Attributes
       static constexpr _Tp 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.

Author

       Generated automatically by Doxygen for libstdc++ from the source code.

                                            libstdc++          std::__is_fast_hash< _Hash >(3cxx)