< cpp | experimental | optional
|(library fundamentals TS)|
If the object contains a value and the type
T is not trivially destructible (see std::is_trivially_destructible), destroys the contained value by calling its destructor, as if by val->T::~T().
Otherwise, does nothing.
T is trivially-destructible, then this destructor is also trivial, so
optional<T> is also trivially-destructible.