void push_back( CharT ch );
Appends the given character
ch to the end of the string.
|ch||-||the character to append|
 Return value
If an exception is thrown for any reason, this function has no effect (strong exception guarantee). (since C++11)
If the operation would result in
size() > max_size(), throws std::length_error.
 See also
| removes the last character
(public member function)