C++ named requirements: Erasable
Specifies that an object of the type can be destroyed by a given Allocator.
T is Erasable from the Container
value_type is identical to
T if, given
||an allocator type|
|| an lvalue of type |
|| the pointer of type |
X::allocator_type is identical to std::allocator_traits<A>::rebind_alloc<T>,
the following expression is well-formed:
X is not allocator-aware, the term is defined as if
A were std::allocator<T>, except that no allocator object needs to be created, and user-defined specializations of std::allocator are not instantiated.
All standard library containers require that their element type satisfies Erasable.
With the default allocator, this requirement is equivalent to the validity of p->~T(), which accepts class types with accessible destructors and all scalar types, but rejects array types, function types, reference types, and void.