C++ concepts: MoveInsertable (since C++11)
Specifies that a rvalue of the type can be copied in uninitialized storage.
[edit] Requirements
The type T is MoveInsertable into the Container X if, given
A
|
the allocator type defined as X::allocator_type
|
m
|
the lvalue of type A obtained from X::get_allocator()
|
p
|
the pointer of type T* prepared by the container
|
rv
|
rvalue expression of type T, provided as the argument to push_back(), etc
|
the following expression is well-formed:
std::allocator_traits<A>::construct(m, p, rv);
And after evaluation, the value of *p is equivalent to the value formerly held by rv (rv remains valid, but unspecified)
[edit] Notes
If A is std::allocator<T>, then this will call placement-new, as by ::new((void*)p) T(rv).
If std::allocator<T> or a similar allocator is used, a class does not have to implement a move constructor to satisfy this type requirement: a copy constructor that takes a const T& argument can bind rvalue expressions. If a MoveInsertable class implements a move constructor, it may also implement move semantics to take advantage of the fact that the value of rv after construction is unspecified.
[edit] See Also
CopyInsertable
|