std::basic_ostream<CharT,Traits>::tellp
Min standard notice:
Returns the output position indicator of the current associated streambuf object.
# Declarations
pos_type tellp();
# Return value
current output position indicator on success, pos_type(-1) if a failure occurs.
# Example
#include <iostream>
#include <sstream>
int main()
{
std::ostringstream s;
std::cout << s.tellp() << '\n';
s << 'h';
std::cout << s.tellp() << '\n';
s << "ello, world ";
std::cout << s.tellp() << '\n';
s << 3.14 << '\n';
std::cout << s.tellp() << '\n' << s.str();
}