std::string, wstring, u16/32string clarification
c++, std, string, unicode
Solution
The difference is that the details of `char` and `wchar_t` are implementation defined, while the encoding of `char16_t` and `char32_t` are explicitly defined by the C++11 standard.
This means that `wstring` is likely to store the same data as either `u16string` or `u32string`, but we don't know which one. And it is allowed for some odd implementation to make them all different, as the size and encoding of the old char types are just not defined by the standard.
Problem
My current understanding of the difference between `std::string` and `std::wstring` is simply the buffer's type; namely, `char` vs `wchar_t`, respectively. I've also read that most (if not all) linux distros use `char` for any and all strings, both ASCII as well as UTF, where Windows is the primary OS that uses `wchar_t` anymore. However, there are a few more string types that I want to get straight in my head: `u16string` and `u32string`, which are strings with 2-byte and 4-byte buffers, respectively. So, my question is this: On platforms with `sizeof(wchar_t) == 2`, is `std::wstring` functionally equivalent to `std::u16string`, as well as platforms with `sizeof(wchar_t) == 4` and `std::u32string`?