std::function::operator=
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                    | function& operator=( const function& other ); | (1) | (since C++11) | 
| function& operator=( function&& other ); | (2) | (since C++11) | 
| function& operator=( std::nullptr_t ); | (3) | (since C++11) | 
| template< class F >  function& operator=( F&& f ); | (4) | (since C++11) | 
| template< class F >  function& operator=( std::reference_wrapper<F> f ); | (5) | (since C++11) | 
Assigns a new target to std::function.
1) Assigns a copy of target of 
other, as if by executing function(other).swap(*this);2) Moves the target of 
other to *this. other is in a valid state with an unspecified value.3) Drops the current target. *this is empty after the call.
4) Sets the target of *this to the callable 
f, as if by executing function(std::forward<F>(f)).swap(*this);. This operator does not participate in overload resolution unless f is Callable for argument types Args... and return type R. (since C++14)5) Sets the target of *this to a copy of 
f, as if by executing function(f).swap(*this);| Contents | 
[edit] Parameters
| other | - | another std::functionobject to copy the target of | 
| f | - | a callable to initialize the target with | 
| Type requirements | ||
| - Fmust meet the requirements ofCallable. | ||
[edit] Return value
*this
[edit] Exceptions
1-2) (none)
3) 
| (none) | (until C++17) | 
| noexcept specification:   noexcept | (since C++17) | 
4) (none)
5) 
noexcept specification:  
noexcept
  [edit] Notes
The move assignment operator uses the default allocator rather than the allocator of *this or the allocator of other (LWG #2386)
[edit] See also
| (until C++17) | assigns a new target (public member function) | 


