namespace console {
  void pause()
  {
    //...
  }
}

#include <iostream>
#include <limits>
 
namespace console {
  void pause() {
    std::cout << "Press ENTER to continue...";
    std::cin.ignore( std::numeric_limits<std::streamsize>::max(), '\n' );
    }
  }

#include <iostream>
#include <windows.h>
 
namespace console {
  void pause() {
    DWORD        mode;
    HANDLE       hin;
    INPUT_RECORD inrec;
    DWORD        count;
 
    // Instruct the user
    std::cout << "Press the 'any' key...";
 
    // Set the console mode to no-echo, raw input,
    // and no window or mouse events.
    hin = GetStdHandle( STD_INPUT_HANDLE );
    GetConsoleMode( hin, &mode );
    SetConsoleMode( hin, 0 );
 
    // Wait for and get a single key press
    do ReadConsoleInput( hin, &inrec, 1, &count );
    while (inrec.EventType != KEY_EVENT);
 
    // Restore the original console mode
    SetConsoleMode( hin, mode );
    }
  }

int main() {
 
  std::cout << "Hello world!\n" << std::endl;
 
  console::pause();
 
  std::cout << "\n\nThank you!" << std::endl;
 
  return EXIT_SUCCESS;
  }