On: Go Slices Are Fat Pointers

[MaulingMonkey]

    -Werror-sizeof-pointer-div

Or in C++:

    #include <type_traits>

    template < typename T, std::size_t N >
    constexpr std::size_t count_of(const T (&)[N]) { return N; }

    #define COUNTOF(a) std::integral_constant<std::size_t, count_of(a)>::value

(C++03 friendly versions are entirely possible, but left as an exercise to the reader)