How to write 'n' copies of a character to ostream like in python

Question

In python, the following instruction: print \'a\'*5 would output aaaaa. How would one write something similar in C++ in conjunction with std:

Answer 1

Use some tricky way: os << setw(n) << setfill(c) << ""; Where n is number of char c to write

Answer 2

In C++20 you'll be able to use std::format to do this:

std::cout << std::format("{:a<5}", "");

Output:

aaaaa

In the meantime you can use the {fmt} library, std::format is based on. {fmt} also provides the print function that makes this even easier and more efficient (godbolt):

fmt::print("{:a<5}", "");

Disclaimer: I'm the author of {fmt} and C++20 std::format.

Answer 3

You can do something like that by overloading the * operator for std::string. Here is a small example

#include<iostream>
#include<string>
std::string operator*(const std::string &c,int n)
{
    std::string str;
    for(int i=0;i<n;i++)
    str+=c;
    return str;
}
int main()
{
    std::string str= "foo";
    std::cout<< str*5 <<"\n";
}

Answer 4

The obvious way would be with fill_n:

std::fill_n(std::ostream_iterator<char>(std::cout), 5, 'a');

Another possibility would be be to just construct a string:

std::cout << std::string(5, 'a');