RE: [boost] PREPROCESSOR library updated

From: Beman Dawes (bdawes_at_[hidden])
Date: 2001-11-25 21:43:50

At 12:16 PM 11/24/2001, Aleksey Gurtovoy wrote:

 >4) Bad news - Metrowerks Codewarrior 7.0 has a bug in preprocessor (to be
 >more concrete, in function-like macro replacement mechanism) that 
restricts
 >usage of the library to only very simple cases, at least if you don't 
write
 >code that specifically address this issue; for example, the above
 >NUMBERED_EXPRESSION example doesn't compile on CW 7.0. Below is a simple
 >test case that reproduces the bug:
 >
 >    #define IDENTITY_MACRO(x) IDENTITY_MACRO_BODY(x)
 >    #define IDENTITY_MACRO_BODY(x) x
 >    #define COMMA_TOKEN() ,
 >
 >    int a IDENTITY_MACRO(COMMA_TOKEN)() b; // this works
 >    int c IDENTITY_MACRO(IDENTITY_MACRO(COMMA_TOKEN))() d; // this 
doesn't
 >
 >Basically, what's happening here is that function-like COMMA_TOKEN macro
 >gets expanded _inside_ of the nested IDENTITY_MACRO call - even although
 >it's NOT followed by a '(' as the next preprocessing token - which is a
 >clearly an incorrect behavior (see 16.3 [cpp.replace] para 9 for the
 >detailed description of the function-like macro replacement process). I
 >haven't submitted bug report yet, but I am going to.

Whoever checks PREPROCESSOR into CVS, please make sure that a regression 
test is added to root/status/regression.cfg so that the above bug is 
illuminated.

--Beman