Moving C++ bindings in gmpxx.h into a namespace

[Marc Glisse]

On Sat, 29 Jun 2013, Sam Varshavchik wrote:

> Is there any interest in moving all the C++ bindings into their own 
> namespace, say gnu::mp?

Vaguely. Preferably at the same time as some other ABI-breaking changes.

> This is popular with many C++ dev libraries, like boost, for example.
> There are several advantages with doing that; mainly reducing the risk of 
> clashing with application's own symbols, or even with symbols from other 
> libraries that an app also links to.

The risk of clashing is very low. We currently use the old C namespacing 
technique of giving all names an application-specific prefix (plus we 
illegally put most names in the implementation namespace). Did you hit a 
particular issue or are you just suggesting it because it sounds good?

> I can prepare a patch to do that, if there's interest.
>
> Compatibility with existing code is trivial.

Binary compatibility is trivially broken. And some odd programs would also 
fail to compile (though that might be acceptable).

> Either provide a separate file that existing code can include, that 
> contains a grand total of three typedefs:
>
> typedef gnu::mp::mpz_class mpz_class;
> typedef gnu::mp::mpf_class mpf_class;
> typedef gnu::mp::mpq_class mpq_class;

You forgot gmp_randclass at least (and "using" is shorter than typedef).

> Or, for 100% source backwards compatibility, rename gmpxx.h to something 
> else, and have it declare everything in gnu::mp, and replace gmpxx.h with a 
> stub that includes the real file, and provides the three typedefs.

I'd probably import the names to the global namespace by default anyway, 
so no point complicating things too much.

-- 
Marc Glisse