std::function::function
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< cpp | utility | functional | function
| function(); |
(1) | (since C++11) |
| function( std::nullptr_t ); |
(2) | (since C++11) |
| function( const function& other ); |
(3) | (since C++11) |
| function( function&& other ); |
(4) | (since C++11) |
| template< class F > function( F f ); |
(5) | (since C++11) |
| template< class Alloc > function( std::allocator_arg_t, const Alloc& alloc ); |
(6) | (since C++11) (until C++17) |
| template< class Alloc > function( std::allocator_arg_t, const Alloc& alloc, |
(7) | (since C++11) (until C++17) |
| template< class Alloc > function( std::allocator_arg_t, const Alloc& alloc, |
(8) | (since C++11) (until C++17) |
| template< class Alloc > function( std::allocator_arg_t, const Alloc& alloc, |
(9) | (since C++11) (until C++17) |
| template< class F, class Alloc > function( std::allocator_arg_t, const Alloc& alloc, F f ); |
(10) | (since C++11) (until C++17) |
Constructs a std::function from a variety of sources.
1-2) Creates an empty function.
3-4) Copies (3) or moves (4) the target of
other to the target of *this. If other is empty, *this will be empty after the call too. For (4), other is in a valid but unspecified state after the call.5) Initializes the target with a copy of
f. If f is a null pointer to function or null pointer to member, *this will be empty after the call. This constructor does not participate in overload resolution unless f is Callable for argument types Args... and return type R. (since C++14)6-10) Same as (1-5) except that
alloc is used to allocate memory for any internal data structures that the function might use.When the target is a function pointer or a std::reference_wrapper, small object optimization is guaranteed, that is, these targets are always directly stored inside the std::function object, no dynamic allocation takes place. Other large objects may be constructed in dynamic allocated storage and accessed by the std::function object through a pointer.
[edit] Parameters
| other | - | the function object used to initialize *this |
| f | - | a callable used to initialize *this |
| alloc | - | an Allocator used for internal memory allocation
|
| Type requirements | ||
-F must meet the requirements of Callable and CopyConstructible.
| ||
-Alloc must meet the requirements of Allocator.
| ||
[edit] Exceptions
1-2)
noexcept specification:
noexcept
3,4,8,9) does not throw if
other's target is a function pointer or a std::reference_wrapper, otherwise may throw std::bad_alloc or any exception thrown by the constructor used to copy or move the stored callable object.5,10) does not throw if
f is a function pointer or a std::reference_wrapper, otherwise may throw std::bad_alloc or any exception thrown by the copy constructor of the stored callable object.6-7)
noexcept specification:
noexcept
[edit] Example
| This section is incomplete Reason: no example |