std::optional<T>::reset

#include <iostream>
#include <optional>
 
struct A
{
 std::string s;
 A(std::string str) : s(std::move(str)) { std::cout << " constructed\n"; }
 ~A() { std::cout << " destructed\n"; }
 A(const A& o) : s(o.s) { std::cout << " copy constructed\n"; }
 A(A&& o) : s(std::move(o.s)) { std::cout << " move constructed\n"; }
 
 A& operator=(const A& other)
 {
 s = other.s;
 std::cout << " copy assigned\n";
 return *this;
 }
 
 A& operator=(A&& other)
 {
 s = std::move(other.s);
 std::cout << " move assigned\n";
 return *this;
 }
};
 
int main()
{
 std::cout << "Create empty optional:\n";
 std::optional <A> opt;
 
 std::cout << "Construct and assign value:\n";
 opt = A("Lorem ipsum dolor sit amet, consectetur adipiscing elit nec.");
 
 std::cout << "Reset optional:\n";
 opt.reset();
 std::cout << "End example\n";
}

Create empty optional:
Construct and assign value:
 constructed
 move constructed
 destructed
Reset optional:
 destructed
End example