[GiNaC-devel] new tinfos

[Richard B. Kreckel]

Hi!

Jens Vollinga wrote:

>> I don't know how to solve the problem of namespace 
>> collision/ambiguity with built-in function like sin,cos,... yet. But 
>> even in the current implementation a get an ambiguity for stuff like
>> cout << sin(1) << endl;
>> when both cmath and GiNaC are included and all their namespace 
>> members are us'ing'ed.
>
>
> just to fill the void:
>
> 1.
> We could rename the functions: tan->Tan,... etc.
> (I don't like this. It's cowardice.)
>
> 2.
> We could write some pre-processor definitions like
> #define sin GiNaC::sin
> ...
> (Well, maybe. These definition could be packed in a convenience header 
> for the user like #include <GiNaC/GiNaC_with_cmath>. But better not to 
> include this header multiple times ...)

I fear this will cause even more problems.

> 3.
> Don't avoid the ambiguities and force the user to explicitly write the 
> namespace for such functions (and make lots of comments about it in 
> the manual/tutorial).
> (Yes, use the force! Maybe give the user some extra header like in 2. 
> to ease the situation). 

This is a patch to the wrong location, since function.h is generated.  
But doesn't it resolve the worst ambiguities where there is a conflict 
with cmath's template<typename _Tp> typename __enable_if<double, 
__is_integer<_Tp>::__value>::__type sin(_Tp)?

--- function.h.old      2005-11-21 21:43:16.063691034 +0100
+++ function.h  2005-11-21 21:42:19.964061214 +0100
@@ -39,6 +39,15 @@
 #define DECLARE_FUNCTION_1P(NAME) \
 class NAME##_SERIAL { public: static unsigned serial; }; \
 const unsigned NAME##_NPARAMS = 1; \
+const GiNaC::function NAME(const ex & p1) { \
+       return GiNaC::function(NAME##_SERIAL::serial, p1); \
+} \
+const GiNaC::function NAME(int p1) { \
+       return GiNaC::function(NAME##_SERIAL::serial, GiNaC::ex(p1)); \
+} \
template<typename T1> const GiNaC::function NAME(const T1 & p1) { \
        return GiNaC::function(NAME##_SERIAL::serial, GiNaC::ex(p1)); \
 }

Cheers
  -richy.

-- 
Richard B. Kreckel
<http://www.ginac.de/~kreckel/>