std::hash <std::variant>

 

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in_placein_place_typein_place_indexin_place_tin_place_type_tin_place_index_t

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std::variant

Member functions

variant::variant

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variant::operator=

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variant::index

variant::valueless_by_exception

Modifiers

variant::emplace

variant::swap

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visit

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get

get_if

operator==operator!=operator<operator<=operator>operator>=

swap

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monostate

bad_variant_access

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hash

uses_allocator

Helper objects

variant_npos

 

Defined in header <variant>
template <class... Types> struct hash<std::variant<Types...>>;		(since C++17)

The template specialization of std::hash for the std::variant template allows users to obtain hashes of variant objects.

The specialization std::hash<std::variant<Types...>> is enabled (see std::hash) if every specialization in std::hash<std::remove_const_t<Types>>... is enabled, and is disabled otherwise.

The member functions of this specialization are not guaranteed to be noexcept.

Template parameters

Types

-

the types of the alternatives supported by the variant object

Notes

Unlike std::hash<std::optional>, hash of a variant does not typically equal the hash of the contained value; this makes it possible to distinguish std::variant<int, int> holding the same value as different alternatives.

See also

hash (C++11)

hash function object (class template)