Wide-character handling in C++

len.cpp

#include <cstdlib>
#include <iostream>
#include <locale>
#include <stdexcept>

int main() {
    std::string line;
    std::string input;
    std::size_t bytes = 0;
    std::size_t characters = 0;

    try {
        std::locale::global(std::locale(""));
    }
    catch (std::runtime_error const& e) {
        std::cout << e.what() << "\n";
        return 1;
    }

    std::cout << "Using locale: " << std::locale().name() << "\n";

    while (getline(std::cin, line)) {
        input += line + "\n";
        bytes += line.length();
        for (
                std::size_t i = 0;
                i < line.length();
                i+= std::mblen(line.c_str() + i, line.length() - i)
        )
            ++characters;
    }

    std::cout << input;
    std::cout << bytes << " bytes " << characters << " characters\n";
}