C++利用函数模板得到数组的长度

#includetemplate char (&ArraySizeHelper(T (&arr)[N]))[N];#define arraysize(array) (sizeof(ArraySizeHelper(array)))template int ArraySize (T (&arr)[N]){ return N; }int main() { int arr[10]; std::cout << ArraySize(arr) << "," << arraysize(arr) << std::endl; double arr2[20]; std::cout << ArraySize(arr2) << "," << arraysize(arr2) << std::endl; return 0;}