C++ named requirements: CopyInsertable
From cppreference.com
Specifies that an instance of the type can be copy-constructed in-place by a given allocator.
Requirements
The type T is CopyInsertable into the container X whose value_type is identical to T if T is MoveInsertable into X, and, given
A
|
an allocator type |
m
|
an lvalue of type A
|
p
|
the pointer of type T* prepared by the container
|
v
|
expression of type (possibly const) T
|
where 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.
If 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.
Notes
If A is std::allocator<T>, then this will call placement-new, as by ::new((void*)p) T(v)