Re: C++ Headers

Bruce Momjian <pgman@candle.pha.pa.us>

From: Bruce Momjian <pgman@candle.pha.pa.us>
To: pgsql-hackers@postgresql.org
Date: 2001-05-22T21:52:20Z
Lists: pgsql-hackers
> On Tue, May 22, 2001 at 12:19:41AM -0400, Bruce Momjian wrote:
> > > This in fact has happened within ECPG. But since sizeof(bool) is passed to
> > > libecpg it was possible to figure out which 'bool' is requested.
> > > 
> > > Another issue of C++ compatibility would be cleaning up the usage of
> > > 'const' declarations. C++ is really strict about 'const'ness. But I don't
> > > know whether postgres' internal headers would need such a cleanup. (I
> > > suspect that in ecpg there is an oddity left with respect to host variable
> > > declaration. I'll check that later)
> > 
> > We have added more const-ness to libpq++ for 7.2.
> 
> Breaking link compatibility without bumping the major version number
> on the library seems to me serious no-no.
> 
> To const-ify member functions without breaking link compatibility,
> you have to add another, overloaded member that is const, and turn
> the non-const function into a wrapper.  For example:
> 
>   void Foo::bar() { ... }   // existing interface
> 
> becomes
> 
>   void Foo::bar() { ((const Foo*)this)->bar(); }   
>   void Foo::bar() const { ... }   

Thanks.  That was my problem, not knowing when I break link compatiblity
in C++.  Major updated.

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