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

String Modifiers

The string class provides several methods for modifying strings. Most come with an abundance of overloaded versions so that they can be used with string objects, string arrays, individual characters, and iterator ranges.

Appending and Adding

You can append one string to another by using the overloaded += operator or by using an append() method. All throw a length_error exception if the result would be longer than the maximum string size. The += operators let you append a string object, a string array, or an individual character to another string:

basic_string&operator+=(const basic_string&str);
basic_string&operator+=(const charT* s);
basic_string&operator+=(charT c);

The append() methods also let you append a string object, ...