C++ named requirements: CopyInsertable
Specifies that an instance of the type can be copy-constructed in-place by a given allocator.
T is CopyInsertable into the container
value_type is identical to
T is MoveInsertable into
X, and, given
||an allocator type|
|| an lvalue of type |
|| the pointer of type |
|| expression of type (possibly const) |
X::allocator_type is identical to std::allocator_traits<A>::rebind_alloc<T>,
the following expression is well-formed:
std::allocator_traits<A>::construct(m, p, v);
And after evaluation, the value of *p is equivalent to the value of v. The value of v is unchanged.
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.
A is std::allocator<T>, then this will call placement-new, as by ::new((void*)p) T(v)