std::hash<std::indirect>
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std::indirect
hash<std::indirect>
Defined in header
<memory>
template< class T, class Allocator >
struct hash<std::indirect<T, Allocator>>;
(since C++26)
struct hash<std::indirect<T, Allocator>>;
The partial specialization of std::hash for std::indirect allows users to obtain hashes of the objects owned by indirect objects.
The specialization std::hash <std::indirect<T, Allocator>> is enabled if std::hash <T> is enabled, and is disabled otherwise.
When enabled, for an object obj of type std::indirect<T, Allocator>, std::hash <std::indirect<T, Allocator>>()(obj) evaluates to:
- std::hash <T>()(*obj), if obj is not valueless.
- An implementation-defined value, if obj is valueless.
The member functions of this specialization are not guaranteed to be noexcept because the hash of T might throw.
[edit] Example
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