The original list: 
     1 2 3 4 5 6 7 8 9 10 

List after replace:
     1 2 3 4 5 6 11 8 9 10 

List after replace_if:
     13 13 13 4 5 6 11 8 9 10 

List using replace_copy to cout:
     17 17 17 4 5 6 11 8 9 10 

List with all elements output as 19s:
     19 19 19 19 19 19 19 19 19 19