deduction guides for std::weak_ptr
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std::weak_ptr
Member functions
Modifiers
Observers
(C++26)
(C++26)
Non-member functions
Helper classes
(C++20)
Deduction guides(C++17)
Defined in header
<memory>
template< class T >
weak_ptr( std::shared_ptr <T> ) -> weak_ptr<T>;
(since C++17)
weak_ptr( std::shared_ptr <T> ) -> weak_ptr<T>;
One deduction guide is provided for std::weak_ptr to account for the edge case missed by the implicit deduction guides.
[edit] Example
Run this code
#include <memory> int main() { auto p = std::make_shared <int>(42); std::weak_ptr w{p}; // explicit deduction guide is used in this case }