Index: swig/Lib/python/typemaps.i |
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--- swig/Lib/python/typemaps.i (revision 0) |
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+/* ----------------------------------------------------------------------------- |
+ * See the LICENSE file for information on copyright, usage and redistribution |
+ * of SWIG, and the README file for authors - http://www.swig.org/release.html. |
+ * |
+ * typemaps.i |
+ * |
+ * Pointer handling |
+ * These mappings provide support for input/output arguments and common |
+ * uses for C/C++ pointers. |
+ * ----------------------------------------------------------------------------- */ |
+ |
+// INPUT typemaps. |
+// These remap a C pointer to be an "INPUT" value which is passed by value |
+// instead of reference. |
+ |
+/* |
+The following methods can be applied to turn a pointer into a simple |
+"input" value. That is, instead of passing a pointer to an object, |
+you would use a real value instead. |
+ |
+ int *INPUT |
+ short *INPUT |
+ long *INPUT |
+ long long *INPUT |
+ unsigned int *INPUT |
+ unsigned short *INPUT |
+ unsigned long *INPUT |
+ unsigned long long *INPUT |
+ unsigned char *INPUT |
+ bool *INPUT |
+ float *INPUT |
+ double *INPUT |
+ |
+To use these, suppose you had a C function like this : |
+ |
+ double fadd(double *a, double *b) { |
+ return *a+*b; |
+ } |
+ |
+You could wrap it with SWIG as follows : |
+ |
+ %include <typemaps.i> |
+ double fadd(double *INPUT, double *INPUT); |
+ |
+or you can use the %apply directive : |
+ |
+ %include <typemaps.i> |
+ %apply double *INPUT { double *a, double *b }; |
+ double fadd(double *a, double *b); |
+ |
+*/ |
+ |
+// OUTPUT typemaps. These typemaps are used for parameters that |
+// are output only. The output value is appended to the result as |
+// a list element. |
+ |
+/* |
+The following methods can be applied to turn a pointer into an "output" |
+value. When calling a function, no input value would be given for |
+a parameter, but an output value would be returned. In the case of |
+multiple output values, they are returned in the form of a Python tuple. |
+ |
+ int *OUTPUT |
+ short *OUTPUT |
+ long *OUTPUT |
+ long long *OUTPUT |
+ unsigned int *OUTPUT |
+ unsigned short *OUTPUT |
+ unsigned long *OUTPUT |
+ unsigned long long *OUTPUT |
+ unsigned char *OUTPUT |
+ bool *OUTPUT |
+ float *OUTPUT |
+ double *OUTPUT |
+ |
+For example, suppose you were trying to wrap the modf() function in the |
+C math library which splits x into integral and fractional parts (and |
+returns the integer part in one of its parameters).K: |
+ |
+ double modf(double x, double *ip); |
+ |
+You could wrap it with SWIG as follows : |
+ |
+ %include <typemaps.i> |
+ double modf(double x, double *OUTPUT); |
+ |
+or you can use the %apply directive : |
+ |
+ %include <typemaps.i> |
+ %apply double *OUTPUT { double *ip }; |
+ double modf(double x, double *ip); |
+ |
+The Python output of the function would be a tuple containing both |
+output values. |
+ |
+*/ |
+ |
+// INOUT |
+// Mappings for an argument that is both an input and output |
+// parameter |
+ |
+/* |
+The following methods can be applied to make a function parameter both |
+an input and output value. This combines the behavior of both the |
+"INPUT" and "OUTPUT" methods described earlier. Output values are |
+returned in the form of a Python tuple. |
+ |
+ int *INOUT |
+ short *INOUT |
+ long *INOUT |
+ long long *INOUT |
+ unsigned int *INOUT |
+ unsigned short *INOUT |
+ unsigned long *INOUT |
+ unsigned long long *INOUT |
+ unsigned char *INOUT |
+ bool *INOUT |
+ float *INOUT |
+ double *INOUT |
+ |
+For example, suppose you were trying to wrap the following function : |
+ |
+ void neg(double *x) { |
+ *x = -(*x); |
+ } |
+ |
+You could wrap it with SWIG as follows : |
+ |
+ %include <typemaps.i> |
+ void neg(double *INOUT); |
+ |
+or you can use the %apply directive : |
+ |
+ %include <typemaps.i> |
+ %apply double *INOUT { double *x }; |
+ void neg(double *x); |
+ |
+Unlike C, this mapping does not directly modify the input value (since |
+this makes no sense in Python). Rather, the modified input value shows |
+up as the return value of the function. Thus, to apply this function |
+to a Python variable you might do this : |
+ |
+ x = neg(x) |
+ |
+Note : previous versions of SWIG used the symbol 'BOTH' to mark |
+input/output arguments. This is still supported, but will be slowly |
+phased out in future releases. |
+ |
+*/ |
+ |
+%include <typemaps/typemaps.swg> |