ptr_fun
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| Categories: functors, adaptors |
Component type: function |
Prototype
template <class Arg, class Result>
pointer_to_unary_function<Arg, Result>
ptr_fun(Result (*x)(Arg));
template <class Arg1, class Arg2, class Result>
pointer_to_binary_function<Arg1, Arg2, Result>
ptr_fun(Result (*x)(Arg1, Arg2));
Description
Ptr_fun takes a function pointer as its argument and
returns a function pointer adaptor, a type of function object.
It is actually two different functions, not one (that is, the name
ptr_fun is overloaded). If its argument is of type
Result (*)(Arg) then ptr_fun creates a
pointer_to_unary_function, and if its argument is of type
Result (*)(Arg1, Arg2) then ptr_fun creates a
pointer_to_binary_function.
Definition
Defined in the standard header functional, and in the nonstandard
backward-compatibility header function.h.
Requirements on types
The argument must be a pointer to a function that takes either
one or two arguments. The argument type(s) and the return type
of the function are arbitrary, with the restriction that the function
must return a value; it may not be a void function.
Preconditions
Complexity
Example
See the examples in the discussions of pointer_to_unary_function
and pointer_to_binary_function.
Notes
See also
Function Objects, pointer_to_unary_function,
pointer_to_binary_function, Adaptable Unary Function,
Adaptable Binary Function
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