Re: [Swig-user] C# constants

[William S F. <ws...@fu...>]

Santosh Joseph wrote:
> hi,
> I have declared "%csconst(1);"
> but I'm having problems with code that does not compile.
> for example: in my header file:
> #define ID_INVALID           0xFFFFFFFF
> translates to:
>   public const int ID_INVALID = 0xFFFFFFFF;
> this doesn't compile because it can't convert int to uint (without a cast).
> what i want to know is if i can declare the constant to be of type uint instead of int.
> i think i can use the %constant statement in the swig input file to get around this,
> but i have many #defines like above and i don't want the maintenance (i'm just inputting
> my header file directly to swig).
> any suggestions? i also used a typemap (from php's const.i), but that didn't work either.
> thanks for any help.

The caveat as documented is that %csconst(1) does not always work, as 
valid C does not necessarily compile as C#, note that 'int f = 
0xFFFFFFFF;' is perfectly valid in C. You can work around this using a 
typemap:

%typemap(cstype) int ID_INVALID "uint"
#define ID_INVALID           0xFFFFFFFF

Note that the typemap type is int, as that is the inferred type that 
SWIG uses. If you define it as unsigned type, eg:
#define ID_INVALID           0xFFFFFFFFu

then SWIG will know that it is unsigned and use uint in C#.

William