C++ named requirements: MoveAssignable (since C++11)
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Specifies that an instance of the type can be assigned from an rvalue argument.
Requirements
The type
T
satisfies
MoveAssignable
if
Given
-
t, a modifiable lvalue expression of typeT, -
rv, an rvalue expression of typeT.
The following expressions must be valid and have their specified effects.
| Expression | Return type | Return value | Post-conditions |
|---|---|---|---|
| t = rv |
T&
|
t
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If
t
and
rv
do not refer to the same object, the value of
t
is equivalent to the value of
rv
before the assignment.
The new value of
|
Notes
The type does not have to implement
move assignment operator
in order to satisfy this type requirement: a
copy assignment operator
that takes its parameter by value or as a
const Type&
, will bind to rvalue argument.
If a
MoveAssignable
class implements a move assignment operator, it may also implement
move semantics
to take advantage of the fact that the value of
rv
after assignment is unspecified.
See also
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(C++11)
(C++11)
(C++11)
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checks if a type has a move assignment operator
(class template) |
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(C++20)
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specifies that a type is assignable from another type
(concept) |