/************************************************************************** * * negator.cpp - Example program for reversing the sense of predicate * function objects by using function adaptors and function * objects. * * $Id: negator.cpp 550991 2007-06-26 23:58:07Z sebor $ * *************************************************************************** * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed * with this work for additional information regarding copyright * ownership. The ASF licenses this file to you under the Apache * License, Version 2.0 (the "License"); you may not use this file * except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or * implied. See the License for the specific language governing * permissions and limitations under the License. * * Copyright 1994-2006 Rogue Wave Software. * **************************************************************************/ #include // for unary_function #include // for boolalpha #include // for cout, endl #include // Create a new predicate from unary_function. template struct is_odd : public std::unary_function { bool operator() (const Arg &arg1) const { return arg1 % 2 != 0; } }; int main () { std::less less_func; // Use not2 on less. std::cout << std::boolalpha << less_func (1, 4) << '\n' << less_func (4, 1) << '\n' << std::not2 (std::less())(1, 4) << '\n' << std::not2 (std::less())(4, 1) << '\n'; // Create an instance of our predicate. is_odd odd; // Use not1 on our user defined predicate. std::cout << odd (1) << '\n' << odd (4) << '\n' << std::not1 (odd)(1) << '\n' << std::not1 (odd)(4) << std::endl; return 0; }