C++ named requirements: EmplaceConstructible (since C++11)
Specifies that an object of the type can be constructed from a given set of arguments in uninitialized storage by a given allocator.
T is EmplaceConstructible into the Container
value_type is identical to
T) from the arguments
args if, given
||an allocator type|
|| an lvalue of type |
|| the pointer of type |
||zero or more arguments|
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, args);
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.