deductionguidesforstdoptional(3)

deductionguidesforstd::optional - deductionguidesforstd::optional

Synopsis

Defined in header <optional> template<class T> (since C++17) optional(T) -> optional<T>;

One deduction_guide is provided for std::optional to account for the edge cases missed by the implicit deduction guides, in particular, non-copyable arguments and array to pointer conversion

Example

// Run this code

#include <optional>

int main() { int a[2]; std::optional oa{a}; // explicit deduction guide is used in this case }