NAME¶

std::variant::~variant - std::variant::~variant

Synopsis¶

~variant(); (since C++17)
(until C++20)
constexpr ~variant(); (since C++20)

If valueless_by_exception() is true, does nothing. Otherwise, destroys the currently
contained value.

This destructor is trivial if std::is_trivially_destructible_v<T_i> is true for all
T_i in Types....

Example¶

// Run this code

#include <variant>
#include <cstdio>

int main()
{
struct X { ~X() { puts("X::~X();"); } };
struct Y { ~Y() { puts("Y::~Y();"); } };

{
puts("entering block #1");
std::variant<X,Y> var;
puts("leaving block #1");
}

{
puts("entering block #2");
std::variant<X,Y> var{ std::in_place_index_t<1>{} }; // constructs var(Y)
puts("leaving block #2");
}
}

Output:¶

entering block #1
leaving block #1
X::~X();
entering block #2
leaving block #2
Y::~Y();

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
the destructor was not constexpr while
P2231R1 C++20 non-trivial destructors can be constexpr in made constexpr
C++20