[Swig-user] [SWIG csharp] Structure pointer-to-pointer in C#

[Clinton C. <cli...@ya...>]

Hi all,

I am using SWIG to wrap a C library for use in some C#
programs. I have run into the following problem: how
do I wrap calls into the C library that allocate
memory for structs?

I have studied the example that is provided in the
SWIG documentation for the analogous problem in Java
(section 19.9.10 in the 1.3 documentation). The
problem I have is, how can I pass back the C pointer
to the structure that has been allocated by the C
routine?

In JNI, there are facilities to allow the JNI code to
directly access and modify the members of a particular
instance of a class. Unfortunately, these facilities
don't exist for the C# case.

Am I missing something really simple? 

I have contemplated using the [StructLayout...]
attribute using the csattribute typemap, and also
passing by reference a IntPtr object to hold the the C
pointer and then replacing the swigCPtr object when
the P/Invoke call returns. But there has to be a more
elegant solution, right?

Thanks in advance for any aid you can provide.

Clinton Chau


	
		
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