/* ------------------------------------------------------------ * Overloaded operator support The directives in this file apply whether or not you use the -builtin option to SWIG, but operator overloads are particularly attractive when using -builtin, because they are much faster than named methods. If you're using the -builtin option to SWIG, and you want to define python operator overloads beyond the defaults defined in this file, here's what you need to know: There are two ways to define a python slot function: dispatch to a statically defined function; or dispatch to a method defined on the operand. To dispatch to a statically defined function, use %feature("python:"), where is the name of a field in a PyTypeObject, PyNumberMethods, PyMappingMethods, PySequenceMethods, or PyBufferProcs. For example: %feature("python:tp_hash") MyClass "myHashFunc"; class MyClass { public: ... }; %{ // Note: Py_hash_t was introduced in Python 3.2 static Py_hash_t myHashFunc(PyObject *pyobj) { MyClass *cobj; // Convert pyobj to cobj return (cobj->field1 * (cobj->field2 << 7)); } %} NOTE: It is the responsibility of the programmer (that's you) to ensure that a statically defined slot function has the correct signature. If, instead, you want to dispatch to an instance method, you can use %feature("python:slot"). For example: %feature("python:slot", "tp_hash", functype="hashfunc") MyClass::myHashFunc; class MyClass { public: Py_hash_t myHashFunc () const; ... }; NOTE: Some python slots use a method signature which does not match the signature of SWIG-wrapped methods. For those slots, SWIG will automatically generate a "closure" function to re-marshall the arguments before dispatching to the wrapped method. Setting the "functype" attribute of the feature enables SWIG to generate a correct closure function. -------------------------------------------------------------- The tp_richcompare slot is a special case: SWIG automatically generates a rich compare function for all wrapped types. If a type defines C++ operator overloads for comparison (operator==, operator<, etc.), they will be called from the generated rich compare function. If you want to explicitly choose a method to handle a certain comparison operation, you may use a different feature, %feature("python:compare") like this: %feature("python:compare", "Py_LT") MyClass::lessThan; class MyClass { public: bool lessThan(const MyClass& other) const; ... }; ... where "Py_LT" is one of the rich comparison opcodes defined in the python header file object.h. If there's no method defined to handle a particular comparison operation, the default behavior is to compare pointer values of the wrapped C++ objects. -------------------------------------------------------------- For more information about python slots, including their names and signatures, you may refer to the python documentation : http://docs.python.org/c-api/typeobj.html * ------------------------------------------------------------ */ #ifdef __cplusplus #if defined(SWIGPYTHON_BUILTIN) #define %pybinoperator(pyname,oper,functp,slt) %rename(pyname) oper; %pythonmaybecall oper; %feature("python:slot", #slt, functype=#functp) oper; %feature("python:slot", #slt, functype=#functp) pyname; #define %pycompare(pyname,oper,comptype) %rename(pyname) oper; %pythonmaybecall oper; %feature("python:compare", #comptype) oper; %feature("python:compare", #comptype) pyname; #else #define %pybinoperator(pyname,oper,functp,slt) %rename(pyname) oper; %pythonmaybecall oper #define %pycompare(pyname,oper,comptype) %pybinoperator(pyname,oper,,comptype) #endif %pybinoperator(__add__, *::operator+, binaryfunc, nb_add); %pybinoperator(__pos__, *::operator+(), unaryfunc, nb_positive); %pybinoperator(__pos__, *::operator+() const, unaryfunc, nb_positive); %pybinoperator(__sub__, *::operator-, binaryfunc, nb_subtract); %pybinoperator(__neg__, *::operator-(), unaryfunc, nb_negative); %pybinoperator(__neg__, *::operator-() const, unaryfunc, nb_negative); %pybinoperator(__mul__, *::operator*, binaryfunc, nb_multiply); %pybinoperator(__mod__, *::operator%, binaryfunc, nb_remainder); %pybinoperator(__lshift__, *::operator<<, binaryfunc, nb_lshift); %pybinoperator(__rshift__, *::operator>>, binaryfunc, nb_rshift); %pybinoperator(__and__, *::operator&, binaryfunc, nb_and); %pybinoperator(__or__, *::operator|, binaryfunc, nb_or); %pybinoperator(__xor__, *::operator^, binaryfunc, nb_xor); %pycompare(__lt__, *::operator<, Py_LT); %pycompare(__le__, *::operator<=, Py_LE); %pycompare(__gt__, *::operator>, Py_GT); %pycompare(__ge__, *::operator>=, Py_GE); %pycompare(__eq__, *::operator==, Py_EQ); %pycompare(__ne__, *::operator!=, Py_NE); /* Special cases */ %rename(__invert__) *::operator~; %feature("python:slot", "nb_invert", functype="unaryfunc") *::operator~; %rename(__call__) *::operator(); %feature("python:slot", "tp_call", functype="ternarycallfunc") *::operator(); #if defined(SWIGPYTHON_BUILTIN) %pybinoperator(__nonzero__, *::operator bool, inquiry, nb_nonzero); %pybinoperator(__truediv__, *::operator/ , binaryfunc, nb_divide); #else %feature("shadow") *::operator bool %{ def __nonzero__(self): return $action(self) __bool__ = __nonzero__ %}; %rename(__nonzero__) *::operator bool; %feature("shadow") *::operator/ %{ def __truediv__(self, *args): return $action(self, *args) __div__ = __truediv__ %}; %rename(__truediv__) *::operator/; %pythonmaybecall *::operator/; #endif /* Ignored operators */ %ignoreoperator(LNOT) operator!; %ignoreoperator(LAND) operator&&; %ignoreoperator(LOR) operator||; %ignoreoperator(EQ) *::operator=; %ignoreoperator(PLUSPLUS) *::operator++; %ignoreoperator(MINUSMINUS) *::operator--; %ignoreoperator(ARROWSTAR) *::operator->*; %ignoreoperator(INDEX) *::operator[]; /* Inplace operator declarations. They translate the inplace C++ operators (+=, -=, ...) into the corresponding python equivalents(__iadd__,__isub__), etc, disabling the ownership of the input 'this' pointer, and assigning it to the returning object: %feature("del") *::Operator; // disables ownership by generating SWIG_POINTER_DISOWN %feature("new") *::Operator; // claims ownership by generating SWIG_POINTER_OWN This makes the most common case safe, ie: A& A::operator+=(int i) { ...; return *this; } ^^^^ ^^^^^^ will work fine, even when the resulting python object shares the 'this' pointer with the input one. The input object is usually deleted after the operation, including the shared 'this' pointer, producing 'strange' seg faults, as reported by Lucriz (lucriz@sitilandia.it). If you have an interface that already takes care of that, ie, you already are using inplace operators and you are not getting seg. faults, with the new scheme you could end with 'free' elements that never get deleted (maybe, not sure, it depends). But if that is the case, you could recover the old behaviour using %feature("del","0") A::operator+=; %feature("new","0") A::operator+=; which recovers the old behaviour for the class 'A', or if you are 100% sure your entire system works fine in the old way, use: %feature("del","") *::operator+=; %feature("new","") *::operator+=; The default behaviour assumes that the 'this' pointer's memory is already owned by the SWIG object; it relinquishes ownership then takes it back. This may not be the case though as the SWIG object might be owned by memory managed elsewhere, eg after calling a function that returns a C++ reference. In such case you will need to use the features above to recover the old behaviour too. */ #if defined(SWIGPYTHON_BUILTIN) #define %pyinplaceoper(SwigPyOper, Oper, functp, slt) %delobject Oper; %newobject Oper; %feature("python:slot", #slt, functype=#functp) Oper; %rename(SwigPyOper) Oper #else #define %pyinplaceoper(SwigPyOper, Oper, functp, slt) %delobject Oper; %newobject Oper; %rename(SwigPyOper) Oper #endif %pyinplaceoper(__iadd__ , *::operator +=, binaryfunc, nb_inplace_add); %pyinplaceoper(__isub__ , *::operator -=, binaryfunc, nb_inplace_subtract); %pyinplaceoper(__imul__ , *::operator *=, binaryfunc, nb_inplace_multiply); %pyinplaceoper(__imod__ , *::operator %=, binaryfunc, nb_inplace_remainder); %pyinplaceoper(__iand__ , *::operator &=, binaryfunc, nb_inplace_and); %pyinplaceoper(__ior__ , *::operator |=, binaryfunc, nb_inplace_or); %pyinplaceoper(__ixor__ , *::operator ^=, binaryfunc, nb_inplace_xor); %pyinplaceoper(__ilshift__, *::operator <<=, binaryfunc, nb_inplace_lshift); %pyinplaceoper(__irshift__, *::operator >>=, binaryfunc, nb_inplace_rshift); /* Special cases */ #if defined(SWIGPYTHON_BUILTIN) %pyinplaceoper(__itruediv__ , *::operator /=, binaryfunc, nb_inplace_divide); #else %delobject *::operator /=; %newobject *::operator /=; %feature("shadow") *::operator /= %{ def __itruediv__(self, *args): return $action(self, *args) __idiv__ = __itruediv__ %}; %rename(__itruediv__) *::operator /=; #endif /* Finally, in python we need to mark the binary operations to fail as 'maybecall' methods */ #define %pybinopermaybecall(oper) %pythonmaybecall __ ## oper ## __; %pythonmaybecall __r ## oper ## __ %pybinopermaybecall(add); %pybinopermaybecall(pos); %pybinopermaybecall(pos); %pybinopermaybecall(sub); %pybinopermaybecall(neg); %pybinopermaybecall(neg); %pybinopermaybecall(mul); %pybinopermaybecall(div); %pybinopermaybecall(truediv); %pybinopermaybecall(mod); %pybinopermaybecall(lshift); %pybinopermaybecall(rshift); %pybinopermaybecall(and); %pybinopermaybecall(or); %pybinopermaybecall(xor); %pybinopermaybecall(lt); %pybinopermaybecall(le); %pybinopermaybecall(gt); %pybinopermaybecall(ge); %pybinopermaybecall(eq); %pybinopermaybecall(ne); #endif