1 /* 2 * Copyright (c) 2015 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_BASE_ARRAYSIZE_H_ 12 #define WEBRTC_BASE_ARRAYSIZE_H_ 13 14 #include <stddef.h> 15 16 // This file defines the arraysize() macro and is derived from Chromium's 17 // base/macros.h. 18 19 // The arraysize(arr) macro returns the # of elements in an array arr. 20 // The expression is a compile-time constant, and therefore can be 21 // used in defining new arrays, for example. If you use arraysize on 22 // a pointer by mistake, you will get a compile-time error. 23 24 // This template function declaration is used in defining arraysize. 25 // Note that the function doesn't need an implementation, as we only 26 // use its type. 27 template <typename T, size_t N> char (&ArraySizeHelper(T (&array)[N]))[N]; 28 29 #define arraysize(array) (sizeof(ArraySizeHelper(array))) 30 31 #endif // WEBRTC_BASE_ARRAYSIZE_H_ 32
