Re: [boost] Re: concept checking for templatize member function?

From: Jeremy Siek (jsiek_at_[hidden])
Date: 2001-09-19 22:50:01

On Thu, 20 Sep 2001, Eric Ford wrote:
eford> Another problem...  When I do a BOOST_CLASS_REQUIRES for a concept
eford> that needs it's namespace explicitly mentioned, I get compile errors
eford> (g++ 2.95 and g++ 2.96).  Is this the known compiler problem that
eford> prevents BOOST_CLASS_REQUIRES from getting more frequent use? The
eford> error messages look like...
eford> DomainInfo.h:84: parse error before `::'
eford> DomainInfo.h:84: parse error before `::'
eford> DomainInfo.h:84: missing ';' before right brace
eford> DomainInfo.h:84: syntax error before `::'

Yes, this is a serious problem with BOOST_CLASS_REQUIRES. I'm
working on a fix... though it may mean completely changing
how this is done.

eford> Also, a stylistic question...  Is it considered good style to do
eford> something like template<class T> struct FooConcept { void
eford> constraints() { function_requires< BarConcept<typename T::return_type>
eford> >(); }; };?  Even if nested those several deep?  They can result in
eford> long error messages, but most of the lines are easy to skip over.  If
eford> that's considered ok, then I have a work around to the above problem.

Yes, for now that is what I recommend doing.

Cheers,
Jeremy

----------------------------------------------------------------------
 Jeremy Siek                          http://php.indiana.edu/~jsiek/
 Ph.D. Student, Indiana Univ. B'ton   email: jsiek_at_[hidden]
 C++ Booster (http://www.boost.org)   office phone: [phone]
----------------------------------------------------------------------