Removes all characters from the string as if by executing erase(begin(), end()).
All pointers, references, and iterators are invalidated.
 Return value
Unlike for std::vector::clear, the C++ standard does not explicitly require that capacity is unchanged by this function, but existing implementations do not change capacity. This means that they do not release the allocated memory (see also shrink_to_fit).
Linear in the size of the string, although existing implementations operate in constant time.
 See also
| removes characters |
(public member function)