QOI issue for -Wchar-subscripts?

Given the following bit of code:

#include <iostream>

const char k12 = '\014';

int main( int argc, char *argv [] )
{
  char str[80];
  char c = 45;
  
  str [ '\n' ] = 'a';
  str [ 23 ] = 'b';
  str [ k12 ] = 'c';
  str [ c ] = 'd';
  
   return 0;
}

and the following invocation:

clang++ ~/junk.cpp -o ~/junk -Wchar-subscripts ; ~/junk

How many warnings should be emitted?

My answer:
  Probably one. Maybe two, since 'k12' is also a char - but it's a constant.

What does clang do?

/Users/marshall/junk.cpp:10:6: warning: array subscript is of type 'char' [-Wchar-subscripts]
        str [ '\n' ] = 'a';
            ^ ~~~~
/Users/marshall/junk.cpp:12:6: warning: array subscript is of type 'char' [-Wchar-subscripts]
        str [ k12 ] = 'c';
            ^ ~~~
/Users/marshall/junk.cpp:13:6: warning: array subscript is of type 'char' [-Wchar-subscripts]
        str [ c ] = 'd';
            ^ ~
3 warnings generated.

Warning on str [ '\n' ] just doesn't seem to be helpful to me.
[ Note: clang emits only two warnings when compiling this code as C ]

What do other people think?

-- Marshall

Marshall Clow Idio Software <mailto:mclow.lists@gmail.com>

A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait).
        -- Yu Suzuki