1#ifndef BENCHMARK_ARRAYSIZE_H_
2#define BENCHMARK_ARRAYSIZE_H_
3
4#include "internal_macros.h"
5
6namespace benchmark {
7namespace internal {
8// The arraysize(arr) macro returns the # of elements in an array arr.
9// The expression is a compile-time constant, and therefore can be
10// used in defining new arrays, for example. If you use arraysize on
11// a pointer by mistake, you will get a compile-time error.
12//
13
14// This template function declaration is used in defining arraysize.
15// Note that the function doesn't need an implementation, as we only
16// use its type.
17template <typename T, size_t N>
18char (&ArraySizeHelper(T (&array)[N]))[N];
19
20// That gcc wants both of these prototypes seems mysterious. VC, for
21// its part, can't decide which to use (another mystery). Matching of
22// template overloads: the final frontier.
23#ifndef COMPILER_MSVC
24template <typename T, size_t N>
25char (&ArraySizeHelper(const T (&array)[N]))[N];
26#endif
27
28#define arraysize(array) (sizeof(::benchmark::internal::ArraySizeHelper(array)))
29
30} // end namespace internal
31} // end namespace benchmark
32
33#endif // BENCHMARK_ARRAYSIZE_H_
34