Re: [boost] [interprocess] Compile problem with 1.39 and trunk

Subject: Re: [boost] [interprocess] Compile problem with 1.39 and trunk
From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2009-08-26 03:58:25

Schrader, Glenn escribió:
> The attached file produces the problem that I'm having. It compiles
> fine using 1.36 thru 1.38. When I use 1.39 or trunk I get the
> following errors (gcc 4.2.3 on 64bit Fedora 9):
> 
> <COMPILER_OUTPUT>
> 
> The compile is looking for 'Dummy::Dummy(const Abcd&)' but that
> constructor parameter is actually non-const. If I change the
> constructor to take a const parameter then the compile succeeds
> (which, of course, isn't what I want). Note that the attached test
> code is boiled down from a more complicated case where I had multiple
> constructor parameters but was seeing the same effect. Obviously,
> something changed between 1.38 and 1.39.

That was a change in the forwarding code. Since perfect forwarding can't 
be achieved in C++03, previously all parameters were taken as const T & 
and then unconsted, this means that sometimes incorrect overload was 
taken (non-const was preferred). Since usually all constructor 
parameters are non-const this was changed. I don't plan to change this 
behaviour, because that would break again code for current users.

> Thanks,
> 
> --glenn

Best,

Ion