The power and insanity of C++ templates

exhibit 12941b: analog literals


it is possible for this to compile as valid c++ code:

  assert( ( o-------------o
            |L             \
            | L             \
            |  L             \
            |   o-------------o
            |   !             !
            !   !             !
            o   |             !
             L  |             !
              L |             !
               L|             !
                o-------------o ).volume == ( o-------------o
                                              |             !
                                              !             !
                                              !             !
                                              o-------------o ).area * int(I-------------I) );

here's more: analog literals
still more: yep, they're turing complete

why, bjorne, why?