The Waite Group's C++ Primer Plus, Third Edition

Appendix F. THE STRING TEMPLATE CLASS

The string class is based on a template definition:

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

Here charT represents the type stored in the string. The traits parameter represents a class that defines necessary properties a type must possess to be represented as a string. For example, it should have a length() method that returns the length of a string represented as an array of type charT. The end of such an array is indicated by the value charT (0), the generalization of the null character. (The expression charT(0) is a type cast of 0 to type charT. It could be just a 0, as it is for type char, or, more generally, it could be an ...