Re: [boost] Interest for a perl6-like-junctions-class?

From: Florian Stegner (FlSt_at_[hidden])
Date: 2005-08-18 09:43:03

David Abrahams wrote:
> Rob Stewart <stewart_at_[hidden]> writes:
>>
>>   1 seems pretty good because the two-character operators stand
>>   out well.  2 works pretty well, but I'm concerned that the
>>   operators may get lost if the predicate is a specialization of
>>   a template type; the template argument list uses the same
>>   tokens.  (1 is better in that case because of the doubled
>>   tokens.)
> 
> 
> None of them look right to me.  Unless you close up the spaces next to
> some_predicate(), they appear to be doing what the usual C++ operators
> do.  a < b looks like less-than; a <b  immediately starts to suggest
> something else.

Hmm.. << >> would be look ok for me, because multivalues don´t provide 
arithmetic operations and they can't be misunderstood in this context. 
But at all, I don´t like this misuse of operator overloads, because it 
can lead into complex and confusing compiler error messages. My appraoch 
is still to provide a simple predicate-function like compare( all_off( a 
), pred(), any_of( b ) ). This has also the advantage, that there are no 
ambigous problems with operator overloads of lambda expressions, which 
occour if you write something like
all_of( a ) << lambda::_1 > lambda::_2 >> any_of( b ).. Where also 
parentheses don't help.

Sincerely
   Florian