I agree with much of what the top-voted answer says, with the exception of the criticism of wchar_t. wchar_t is not equal to utf-16: it is supposed to be a typ

I agree with much of what the top-voted answer says, with the exception of the criticism of wchar_t. wchar_t is not equal to utf-16: it is supposed to be a type large enough to store any single codepoint. Environments where wchar_t is utf-16 simply have a broken wchar_t - when wchar_t is ucs4 then it fulfills its original purpose.