C++ Primer Plus

String Varieties

This section treats the string class as if it were based on the char type. In fact, as mentioned earlier, the string library really is based on a template class:

template<class charT, class traits = char _traits<charT>,        class Allocator = allocator<charT> >basic_string {...};

The basic_string template comes with four specializations, each of which has a typedef name:

typedef basic_string<char> string;typedef basic_string<wchar_t> wstring;typedef basic_string<char16_t> u16string;   // C++11typedef basic_string<char32_t> u32string ;  // C++11

This allows you to use strings based on the wchar_t, char16_t, and char32_t types as well as the char type. You could even develop some sort of character-like class and use the basic_string ...