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Blitz Support : |
From: Julian Cummings (cummings_at_[hidden])
Date: 2005-06-02 13:47:09
Hello Lukasz,
I guess it wouldn't do any harm to go ahead and put parentheses around
min and max in these blitz header files, just to sidestep this potential
problem. I hope you will contact the folks who maintain boost and let
them know about this problem. Their code is just a problem waiting to
happen, and they should really address this.
Regards, Julian C.
On Thu, 2005-06-02 at 09:28 +0100, Lukasz Dobrek wrote:
> Hi Julian,
>
> Thank you for your answer. I managed to solve it by myself, but
> anyway thank you.
>
> I agree with you that it is a dangerous practice to leave this to macros
> underfined on the other hand blitz could go around this problem by
> bracketing each min and max. I.e. instead of writing
>
> template<P>
> P min( Vector<P> const & a ){ ... }
> write:
> template<P>
> P (min)( Vector<P> const & a ){ ... }
>
> I cannot honestly say that I think it is a good solution. The good
> solution is probably to
> convince boost people to undef min and max. But it is also a solution, it makes
> blitz beinng less (other parties) errors prone.
>
>
>
> On 6/1/05, Julian Cummings <cummings_at_[hidden]> wrote:
> > Hello Lukasz,
> >
> > Apparently boost is defining a macro called "min" that is interfering with
> > blitz when it attempts to define a function called "min" in
> > <blitz/vecmin.cc>. Defining macros with very generic names like "min" in
> > header files and then leaving them defined in user code is a *very* bad
> > idea.
> >
> > A simple workaround would be to undefine "min" somewhere near the start of
> > <blitz/vecmin.cc>:
> >
> > #ifdef min
> > #undef min
> > #endif
> >
> > The only problem with this is that if for some crazy reason boost really
> > needs this macro sometime later on in the code, it will be gone. You might
> > want to search in the boost headers to determine where the macro min is
> > defined and used. The proper solution is for the boost headers to undefine
> > the min macro when it is no longer needed, so that it does not pollute other
> > code like this. Incidentally, you may discover a similar problem with "max"
> > and the header file <blitz/vecmax.cc>, since min and max usually occur
> > together.
> >
> > Regards, Julian C.
> >
> > Dr. Julian C. Cummings
> > Staff Scientist, CACR/Caltech
> > (626) 395-2543
> > cummings_at_[hidden]
> >
> >
> > > -----Original Message-----
> > > From: blitz-support-bounces_at_[hidden]
> > > [mailto:blitz-support-bounces_at_[hidden]] On Behalf Of
> > > Lukasz Dobrek
> > > Sent: Thursday, May 26, 2005 6:40 AM
> > > To: blitz-support_at_[hidden]
> > > Subject: [Blitz-support] blitz + boost problems
> > >
> > > Hi
> > > I have a problem with using in the same project blitz-0.8
> > > and boost-1.32, I use VS .NET environment. I didn't test it
> > > with other compilers, so I don't know whether it is
> > > reproducable in different setings, but:
> > >
> > > this works:
> > >
> > > #include <blitz/array.h>
> > > #include <boost/date_time/posix_time/posix_time.hpp>
> > > void test()
> > > {
> > >
> > > }
> > > while this:
> > >
> > > #include <boost/date_time/posix_time/posix_time.hpp>
> > > #include <blitz/array.h>
> > > void test()
> > > {
> > > }
> > >
> > > does not. It failes with plenty of syntax errors:
> > >
> > > c:\ALM_Hybrid\blitz\blitz\vecmin.cc(59) : warning C4003: not
> > > enough actual parameters for macro 'min'
> > > c:\ALM_Hybrid\blitz\blitz\vecmin.cc(59) : error C2226: syntax error :
> > > unexpected type 'blitz::Vector<P_numtype>'
> > > c:\ALM_Hybrid\blitz\blitz\vecmin.cc(59) : error C2988:
> > > unrecognizable template declaration/definition
> > > c:\ALM_Hybrid\blitz\blitz\vecmin.cc(59) : error C2059: syntax
> > > error : ')'
> > > c:\ALM_Hybrid\blitz\blitz\vecmin.cc(59) : error C2059: syntax
> > > error : ')'
> > > c:\ALM_Hybrid\blitz\blitz\vecmin.cc(67) : error C2653:
> > > 'P_expr' : is not a class or namespace name
> > > c:\ALM_Hybrid\blitz\blitz\vecmin.cc(67) : error C2146: syntax error :
> > > missing ',' before identifier 'T_numtype'
> > > c:\ALM_Hybrid\blitz\blitz\vecmin.cc(67) : error C2065: 'T_numtype' :
> > > undeclared identifier
> > >
> > > and so on and on.
> > >
> > >
> > > I don't know whether it is more blitz or more boost issue,
> > > but As the errors appear to come from Blitz I send it first heare.
> > >
> > > Regrads
> > > Lukasz
> > >
> > > _______________________________________________
> > > Blitz-support mailing list
> > > Blitz-support_at_[hidden]
> > > http://www.oonumerics.org/mailman/listinfo.cgi/blitz-support
> > >
> > >
> >
> >
> >
>
-- Dr. Julian C. Cummings E-mail: cummings_at_[hidden] California Institute of Technology Phone: 626-395-2543 1200 E. California Blvd., Mail Code 158-79 Fax: 626-584-5917 Pasadena, CA 91125 Office: 125 Powell-Booth