Re: [Boost-users] [Proto] implementing an computer algebra systemwith proto

Subject: Re: [Boost-users] [Proto] implementing an computer algebra systemwith proto
From: Kim Kuen Tang (kuentang_at_[hidden])
Date: 2009-01-28 16:18:13

Dave Jenkins schrieb:
>
> Below is an example program showing what I mean.
> I would expect that only placeholder1 would match,
> but both placeholder1 and placeholder2 match and produce the same output.
> I even tried using proto::exact to get the program to reject 
> placeholder2, but that made no difference.
>
I see that this is a problem. (What does UB stand for?)
But can a correct implemented grammar be a workaround?
Perhaps we can first check wehter var1_ appears in the expression. If 
not we can return the expression unmodified.

Cheers
Kim Tang