cpp/named req/EmplaceConstructible

Specifies that an object of the type can be constructed from a given set of arguments in uninitialized storage by a given allocator.

Requirements
The type is  into the   (whose  is identical to ) from the arguments  if, given

where is identical to ,

the following expression is well-formed:

If is not allocator-aware or is a std specialization, the term is defined as if  were std, except that no allocator object needs to be created, and user-defined specializations of std are not instantiated.