std::basic_string::capacity
From cppreference.com
                    
                                        
                    < cpp | string | basic string
                    
                                                            
                    |   size_type capacity() const;  | 
||
Returns the number of characters that the string has currently allocated space for.
Contents | 
[edit] Parameters
(none)
[edit] Return value
capacity of the currently allocated storage
[edit] Exceptions
| (none) | (until C++11) | 
| (since C++11) | 
[edit] Complexity
Constant
[edit] See also
|    returns the number of characters   (public member function)  | |
|    reserves storage   (public member function)  | |