d7472b52d6
R=andrew@webrtc.org Review URL: https://webrtc-codereview.appspot.com/39029004 Cr-Commit-Position: refs/heads/master@{#8317} git-svn-id: http://webrtc.googlecode.com/svn/trunk@8317 4adac7df-926f-26a2-2b94-8c16560cd09d
41 lines
1.4 KiB
C++
41 lines
1.4 KiB
C++
/*
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* Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef WEBRTC_BASE_ARRAYSIZE_H_
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#define WEBRTC_BASE_ARRAYSIZE_H_
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#include <stddef.h>
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// This file defines the arraysize() macro and is derived from Chromium's
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// base/macros.h.
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// The arraysize(arr) macro returns the # of elements in an array arr.
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// The expression is a compile-time constant, and therefore can be
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// used in defining new arrays, for example. If you use arraysize on
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// a pointer by mistake, you will get a compile-time error.
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// This template function declaration is used in defining arraysize.
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// Note that the function doesn't need an implementation, as we only
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// use its type.
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template <typename T, size_t N>
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char (&ArraySizeHelper(T (&array)[N]))[N];
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// That gcc wants both of these prototypes seems mysterious. VC, for
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// its part, can't decide which to use (another mystery). Matching of
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// template overloads: the final frontier.
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#ifndef _MSC_VER
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template <typename T, size_t N>
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char (&ArraySizeHelper(const T (&array)[N]))[N];
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#endif
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#define arraysize(array) (sizeof(ArraySizeHelper(array)))
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#endif // WEBRTC_BASE_ARRAYSIZE_H_
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