Add new swigtype_inout.i library containing SWIGTYPE *& OUTPUT typemaps.

Lib/csharp/swigtype_inout.i

@@ -0,0 +1,34 @@
+/* -----------------------------------------------------------------------------
+ * swigtype_inout.i
+ *
+ * Pointer pointer and pointer reference handling typemap library for non-primitive types
+ *
+ * These mappings provide support for input/output arguments and common
+ * uses for C/C++ pointer references and pointer to pointers.
+ *
+ * These are named typemaps (OUTPUT) and can be used like any named typemap.
+ * Alternatively they can be made the default by using %apply:
+ *   %apply SWIGTYPE *& OUTPUT { SWIGTYPE *& }
+ * ----------------------------------------------------------------------------- */
+
+/*
+ * OUTPUT typemaps. Example usage wrapping:
+ *
+ *   void f(XXX *& x) { x = new XXX(111); }
+ *
+ * would be:
+ *
+ *   XXX x = null;
+ *   f(out x);
+ *   // use x
+ *   x.Dispose(); // manually clear memory or otherwise leave out and leave it to the garbage collector
+ */
+%typemap(ctype) SWIGTYPE *& OUTPUT "void **"
+%typemap(imtype, out="global::System.IntPtr") SWIGTYPE *& OUTPUT "out global::System.IntPtr"
+%typemap(cstype) SWIGTYPE *& OUTPUT "out $*csclassname"
+%typemap(csin,
+         pre="    global::System.IntPtr cPtr_$csinput = global::System.IntPtr.Zero;",
+         post="      $csinput = (cPtr_$csinput == global::System.IntPtr.Zero) ? null : new $*csclassname(cPtr_$csinput, true);",
+         cshin="out $csinput") SWIGTYPE *& OUTPUT "out cPtr_$csinput"
+%typemap(in) SWIGTYPE *& OUTPUT %{ $1 = ($1_ltype)$input; %}
+%typemap(freearg) SWIGTYPE *& OUTPUT ""