1 #ifndef BENCHMARK_ARRAYSIZE_H_ 2 #define BENCHMARK_ARRAYSIZE_H_ 3 4 #include "internal_macros.h" 5 6 namespace benchmark { 7 namespace 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. 17 template <typename T, size_t N> 18 char (&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 24 template <typename T, size_t N> 25 char (&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
