std::ptr_fun
From cppreference.com
< cpp | utility | functional
Defined in header <functional>
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template< class Arg, class Result > std::pointer_to_unary_function<Arg,Result> |
(1) | (until C++17) (deprecated since C++11) |
template< class Arg1, class Arg2, class Result > std::pointer_to_binary_function<Arg1,Arg2,Result> |
(2) | (until C++17) (deprecated since C++11) |
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.
Parameters
f | - | pointer to a function to create a wrapper for |
Return value
A function object wrapping f
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Exceptions
(none)
Example
Run this code
#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!