NAME

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
  }