1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 #ifndef GOOGLE_PROTOBUF_MACROS_H__ 32 #define GOOGLE_PROTOBUF_MACROS_H__ 33 34 namespace google { 35 namespace protobuf { 36 37 #undef GOOGLE_DISALLOW_EVIL_CONSTRUCTORS 38 #define GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(TypeName) \ 39 TypeName(const TypeName&) = delete; \ 40 void operator=(const TypeName&) = delete 41 42 #undef GOOGLE_DISALLOW_IMPLICIT_CONSTRUCTORS 43 #define GOOGLE_DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \ 44 TypeName() = delete; \ 45 TypeName(const TypeName&) = delete; \ 46 void operator=(const TypeName&) = delete 47 48 // =================================================================== 49 // from google3/base/basictypes.h 50 51 // The GOOGLE_ARRAYSIZE(arr) macro returns the # of elements in an array arr. 52 // The expression is a compile-time constant, and therefore can be 53 // used in defining new arrays, for example. 54 // 55 // GOOGLE_ARRAYSIZE catches a few type errors. If you see a compiler error 56 // 57 // "warning: division by zero in ..." 58 // 59 // when using GOOGLE_ARRAYSIZE, you are (wrongfully) giving it a pointer. 60 // You should only use GOOGLE_ARRAYSIZE on statically allocated arrays. 61 // 62 // The following comments are on the implementation details, and can 63 // be ignored by the users. 64 // 65 // ARRAYSIZE(arr) works by inspecting sizeof(arr) (the # of bytes in 66 // the array) and sizeof(*(arr)) (the # of bytes in one array 67 // element). If the former is divisible by the latter, perhaps arr is 68 // indeed an array, in which case the division result is the # of 69 // elements in the array. Otherwise, arr cannot possibly be an array, 70 // and we generate a compiler error to prevent the code from 71 // compiling. 72 // 73 // Since the size of bool is implementation-defined, we need to cast 74 // !(sizeof(a) & sizeof(*(a))) to size_t in order to ensure the final 75 // result has type size_t. 76 // 77 // This macro is not perfect as it wrongfully accepts certain 78 // pointers, namely where the pointer size is divisible by the pointee 79 // size. Since all our code has to go through a 32-bit compiler, 80 // where a pointer is 4 bytes, this means all pointers to a type whose 81 // size is 3 or greater than 4 will be (righteously) rejected. 82 // 83 // Kudos to Jorg Brown for this simple and elegant implementation. 84 85 #undef GOOGLE_ARRAYSIZE 86 #define GOOGLE_ARRAYSIZE(a) \ 87 ((sizeof(a) / sizeof(*(a))) / \ 88 static_cast<size_t>(!(sizeof(a) % sizeof(*(a))))) 89 90 } // namespace protobuf 91 } // namespace google 92 93 #endif // GOOGLE_PROTOBUF_MACROS_H__ 94