C++ named requirements: EmplaceConstructible (since C++11) (original) (raw)

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

[edit] Requirements

The type **T** is EmplaceConstructible into the Container **X** (whose value_type is identical to T) from the arguments **args** if, given

A an allocator type
m an lvalue of type A
p the pointer of type T* prepared by the container
args zero or more arguments

where **X::allocator_type** is identical to std::allocator_traits<A>::rebind_alloc<T>,

the following expression is well-formed:

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

[edit] Notes

Although it is required that customized construct is used when constructing elements of std::basic_string until C++23, all implementations only used the default mechanism. The requirement is corrected by P1072R10 to match existing practice.

[edit] See also