Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
At the very minimum for optional<T>
to work with a minimum interface it is required that T
has a publicly accessible no-throw destructor. In that case you need to initialize
the optional object with function emplace() or use InPlaceFactories.
Additionally, if T is Moveable, optional<T>
is also Moveable and can be
easily initialized from an rvalue of type T
and be passed by value. Additionally, if T
is Copyable, optional<T> is
also Copyable and can be easily
initialized from an lvalue of type T.
T is
not required to be Default
Constructible.