How to set maximum field width for a std::string with iomanip?

std::setw() sets the minimum field width for all output, and std::setprecision() is capable of affecting floats, but is there a way to set the maximum field width for a std::string, to achieve the same result as the following printf() format specifier: %10.10s

I am aware that boost::format may be capable of doing this, but I am looking for a solution that is strictly C++ standards only, no third party software.

Solution

There isn't a built in way to do this with C++ streams. One way to do this is to use a std::string_view to just get the slice that you want like

#include <iostream>
#include <string_view>

std::string_view print_max(std::string_view sv, std::size_t width)
{
    return sv.substr(0, width);
}


int main()
{
    std::cout << print_max("0123456789", 3) << "\n";
    std::cout << print_max("0123456789", 5) << "\n";
    std::cout << print_max("0123456789", 8) << "\n";
    std::cout << print_max("0123456789", 20);
}

Output: