std::wcslen (3) - Linux Man Pages
Defined in header <cwchar>
std::size_t wcslen( const wchar_t* str );
Returns the length of a wide string, that is the number of non-null wide characters that precede the terminating null wide character.
The behavior is undefined if there is no null character in the wide character array pointed to by str.
str - pointer to the null-terminated wide string to be examined
The length of the null-terminated wide string str.
// Run this code