std::function::assign (3) Linux Manual Page

std::function<R(Args…)>::assign – std::function<R(Args…)>::assign

Synopsis

template< class F, class Alloc > (since C++11)
void assign( F&& f, const Alloc& alloc ); (removed in C++17)
Initializes the target with f. alloc is used to allocate memory for any internal data structures that the function might use.
Equivalent to function(allocator_arg, alloc, std::forward<F>(f)).swap(*this)

Parameters

f – callable function to initialize the target with
alloc – allocator to use to allocate memory for the internal data structures

Return value

(none)

Exceptions

(none)

See also

assigns a new target

operator= (public member function)