David Abrahams wrote:
Rob Stewart <stewart@sig.com> 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