Re: [Swig-user] passing by reference

[Petr N. <Pet...@am...>]

Hi,

you don't usually primitive types "by reference" in Perl. Instead, you need to treat them as input-output parameters. The idiom is

C++ declaration:
int someFunc(int &parameter);
Perl invocation:
($retval,$parameter) = someFunc($parameter);

I believe you can use INOUT typemaps from the standard swig library. I mean, there used to be bugs in them when I was trying to use them, but according to swig's bugzilla everything seems to work find in swig 2.

Note #1: For non-primitive types where $parameter encapsulates an underlying C++ object, a call by reference is straightforward.
Note #2: It is possible to write a typemap with code that manipulates the input Perl scalar from the C side, but that violates the principle of least surprise; not many Perl coders expect parameters to be changed by methods.

Regards,

--
Petr Novotný
Prague Development Center, AMDOCS
+420266773112, +420608711517
"Great minds discuss ideas; Average minds discuss events; Small minds discuss people." - Eleanor Roosevelt


This message and the information contained herein is proprietary and confidential and subject to the Amdocs policy statement,
you may review at http://www.amdocs.com/email_disclaimer.asp