Re: [Boost-users] [Proto]: How to use complex grammars in a domain/extension

Subject: Re: [Boost-users] [Proto]: How to use complex grammars in a domain/extension
From: Roland Bock (rbock_at_[hidden])
Date: 2010-09-21 04:11:29

On 09/21/2010 09:49 AM, Joel Falcou wrote:
> The following code works here:
>
> // 
> -----------------------------------------------------------------------
> [...]
Yes, I know, but that is not the grammar I need. I want to combine my 
terminal similar to std::string, so that:

std::string a, b;

a; // ok
a + b; // ok
a == b; // ok
a == b + b; // ok
a && a == b; // ERROR

>
> Seems proto::or_ wiht *1* condition acts weird.
> Eric, am I right or am I hallucinating and missing the obvious ?

You can remove the proto::or_ like

struct equation:
       proto::equal_to<addition, addition>
{};

It does not change the result. So it does not look like a problem in 
proto::or_, but maybe a bug in how proto determines the operators of 
extensions?

Regards,

Roland