deductionguidesforstdweak_ptr(3)

deductionguidesforstd::weak_ptr - deductionguidesforstd::weak_ptr

Synopsis

Defined in header <memory> template<class 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.

// 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 }