Defined in header <functional> | ||
|---|---|---|
template< class Arg, class Result >
std::pointer_to_unary_function<Arg,Result>
ptr_fun( Result (*f)(Arg) );
| (1) | (deprecated in C++11) (removed in C++17) |
template< class Arg1, class Arg2, class Result >
std::pointer_to_binary_function<Arg1,Arg2,Result>
ptr_fun( Result (*f)(Arg1, Arg2) );
| (2) | (deprecated in C++11) (removed in C++17) |
Creates a function wrapper object (either std::pointer_to_unary_function or std::pointer_to_binary_function), deducing the target type from the template arguments.
1) Effectively calls std::pointer_to_unary_function<Arg,Result>(f).
2) Effectively calls std::pointer_to_binary_function<Arg1,Arg2,Result>(f).
This function and the related types are deprecated as of C++11 in favor of the more general std::function and std::ref, both of which create callable adapter-compatible function objects from plain functions.
| f | - | pointer to a function to create a wrapper for |
A function object wrapping f.
(none).
#include <string>
#include <iostream>
#include <algorithm>
#include <functional>
bool isvowel(char c)
{
return std::string("aeoiuAEIOU").find(c) != std::string::npos;
}
int main()
{
std::string s = "Hello, world!";
std::copy_if(s.begin(), s.end(), std::ostreambuf_iterator<char>(std::cout),
std::not1(std::ptr_fun(isvowel)));
// C++11 alternatives:
// std::not1(std::cref(isvowel)));
// std::not1(std::function<bool(char)>(isvowel)));
}Output:
Hll, wrld!
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