...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Change the kind to null, discarding the previous contents.
void emplace_null() noexcept;
The value is replaced with a null, destroying the previous contents.
Linear in the size of *this
.
No-throw guarantee.