std::basic_string<CharT,Traits,Allocator>::clear
Min standard notice:
Removes all characters from the string as if by executing erase(begin(), end()).
# Declarations
void clear();
(noexcept since C++11) (constexpr since C++20)
# Return value
(none)
# Notes
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).
# Example
#include <cassert>
#include <iostream>
#include <string>
int main()
{
std::string s{"Exemplar"};
std::string::size_type const capacity = s.capacity();
s.clear();
assert(s.empty());
assert(s.size() == 0);
std::cout << std::boolalpha << (s.capacity() == capacity) << '\n';
}