Finding the amount of rows and columns for a 2-D array in C++

Question

I know in C++ you can get a arrays amount of rows and columns with:

 int rows = sizeof array / sizeof array[0];
 int cols = sizeof array[0] / sizeof array[0][0];

However is there any better way to do this?

Answer 1

In C++11 you can do this using template argument deduction. It seems that the extent type_trait already exists for this purpose:

#include <type_traits>
// ...
int rows = std::extent<decltype(array), 0>::value;
int cols = std::extent<decltype(array), 1>::value;