deductionguidesforstd::optional (3) Linux Manual Page

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
  }