1 /************************************************************** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * 20 *************************************************************/ 21 22 23 24 #ifndef WW_NEEDED_CAST_HXX 25 #define WW_NEEDED_CAST_HXX 26 27 #include <tools/debug.hxx> 28 #include "staticassert.hxx" 29 30 namespace ww 31 { checking_cast(Param in,Ret)32 template<typename Ret, typename Param> Ret checking_cast(Param in, Ret) 33 { 34 return static_cast<Ret>(in); 35 } 36 checking_cast(Ret in,Ret)37 template<typename Ret> Ret checking_cast(Ret in, Ret) 38 { 39 DBG_ASSERT( false, "UnnecessaryCast" ); 40 return in; 41 } 42 43 /* 44 needed_cast is the same as static_cast except that there will be a compile 45 time assert when NDEBUG is not defined and the in and out types are the 46 same. i.e. needed_cast catches unnecessary casts 47 */ needed_cast(Param in)48 template<typename Ret, typename Param> Ret needed_cast(Param in) 49 { 50 /* 51 Massage a single argument and a ret value into two arguments to allow 52 a determination if the dest type is the same as the source type 53 */ 54 return checking_cast(in, Ret()); 55 } 56 } 57 #endif 58 59 /* vim: set noet sw=4 ts=4: */ 60