[Swig-user] std_map.i generates uncompilable code when a map takes a pointer as key

[Philipp K. <oe...@gm...>]

Dear List,
If I try to create a STL-map with a pointer as a key, I get the following
compiler error:
error: `type_name' is not a member of `swig::traits<Key>' (with SWIG 1.3.34
and mingw 3.4.5, same effect in VC++ 8)
The following example code should reproduce the behaviour:
%include "std_map.i"
%module test
%{#include <map> 
struct Value { double  a,b; };
struct Key   { int i; Key(int iIn=0) : i(iIn) {}};
%}
// A structure for the value
struct Value { double  a,b; };
// A structure for the key pointer
struct Key   { int i; Key(int iIn=0) : i(iIn) {}};
// Template for a map, produces illegal code
%template(pIntMap) std::map<Key*,Value>;

1.5 years ago (2006-12-17) Nitro gave for a similar case a workaround,
appending the following code to the .i file
%{
	namespace swig {
     template <>  struct traits<Key> {
       typedef pointer_category category;
       static const char* type_name() { return"Key *"; }
     };
   }

%}
With this workaround the code compiles nicely, but I'm quite sure this is
not the intended behaviour of SWIG. Can it get fixed? Should I report it as
a bug? (Didn't found it in the buglist, but perhaps it is already there)
Another question:
I do not understand the workaround, does it have any side effects? In my
real application the key class is a very imported and of used abstract base
class.

Thank you for any help,

Philipp