The Source RCON Protocol(https://developer.valvesoftware.com/wiki/Source_RCON_Protocol) implementation in cplusplus, depend on asio library. Code example:
#include <iostream>
#include <rcon.hpp>
int main()
{
std::cout << rcon("127.0.0.1", "27015", "password", "echo hello world");
return 0;
}