Re: [boost] PP: MSVC BOOST_PP_REPEAT + BOOST_PP_SEQ_ELEM bug

From: Paul Mensonides (pmenso57_at_[hidden])
Date: 2003-04-11 21:57:53

Aleksey Gurtovoy wrote:
> Preprocessing of the test case below using MSVC 6.5 produces
> 
>     0 0 0 0 0
> 
> instead of expected
> 
>     ( a, b, c ) ( a, b, c ) ( a, b, c ) ( a, b, c ) ( a, b, c )
> 
> Would it be possible to fix that one somehow?
> 
> TIA,
> Aleksey
> 
> 
> #include "boost/preprocessor/repeat.hpp"
> #include "boost/preprocessor/seq/elem.hpp"
> 
> #define b( x, y ) x y
> #define BODY( unused, n, tuple ) tuple
> 
> #define SOMETHING( arity, params ) \
>     BOOST_PP_REPEAT( \
>           arity \
>         , BODY \
>         , ( a, BOOST_PP_SEQ_ELEM(0, params), c ) \
>         ) \
> /**/
> 
> SOMETHING( 5, (b)(d) )

Do the parts work independently?

BOOST_PP_SEQ_ELEM(0, (b)(c)) -> b

BOOST_PP_REPEAT(5, BODY, (a, b, c)) -> (a, b, c) (a, b, c) // etc.

Paul Mensonides