#include <algorithm>
#include <iostream>

int main()
{
  char str[]  = "aBcDeFgH";
  char ziel[] = "--------";
  std::cout << str << '\n';            // aBcDeFgH

  std::copy_if(str, str+8, ziel, [](char c) { return c <= 'Z'; } );

  std::cout << str << '\n';            // BDFH----
}