#include <iostream>
#include <sstream>

int main()
{
    for (char ch = 'a'; ch < 'z'; ++ch)
    {
        std::istringstream is(std::string("2") + ch);

        double val;
        is >> val;

        std::cout << "For \"" << is.str() << "\" val = " << val;
        std::cout << ", buffer = " << is.rdbuf() ;

        if (!std::cout)
            std::cout.clear();

        std::cout << '\n';
    }
}