octave: map unary functions to __...___ Python-style unary members

- Only available in Octave 3.8.0 and higher

Examples/octave/operator/example.i

@@ -31,4 +31,20 @@
      return (double) $self->re();
    }
 
+   double __real__() {
+     return $self->re();
+   }
+   double __imag__() {
+     return $self->im();
+   }
+   double __abs__() {
+     return sqrt($self->re()*$self->re() + $self->im()*$self->im());
+   }
+   ComplexVal __conj__() {
+     return ComplexVal($self->re(), -$self->im());
+   }
+   ComplexVal __exp__() {
+     return exp($self->re()) * ComplexVal(cos($self->im()), sin($self->im()));
+   }
+
 };

Examples/octave/operator/runme.m

@@ -28,3 +28,12 @@ printf("2*a = %s\n",disp(2*a));
 # conversions
 printf("single(a) = %g\n", single(a));
 printf("double(a) = %g\n", double(a));
+
+# unary functions
+if swig_octave_prereq(3,8,0)
+  printf("real(a) = %g\n", real(a));
+  printf("imag(a) = %g\n", imag(a));
+  printf("abs(a) = %g\n", abs(a));
+  printf("conj(a) = %s\n", disp(conj(a)));
+  printf("exp(a) = %s\n", disp(exp(a)));
+endif

Lib/octave/octrun.swg

@@ -824,6 +824,18 @@ SWIGRUNTIME void swig_acquire_ownership_obj(void *vptr, int own);
       return ret.scalar_value();
     }
 
+#if SWIG_OCTAVE_PREREQ(3,8,0)
+    virtual octave_value map(octave_base_value::unary_mapper_t umap) const {
+      const std::string opname = std::string("__") + octave_base_value::get_umap_name(umap) + std::string("__");
+      octave_value ret;
+      if (!dispatch_unary_op(opname, ret)) {
+        error((opname + std::string(" method not found")).c_str());
+        return octave_value();
+      }
+      return ret;
+    }
+#endif
+
 #if SWIG_OCTAVE_PREREQ(3,3,52)
     virtual octave_map map_value() const {
       return octave_map();
@@ -1080,6 +1092,11 @@ SWIGRUNTIME void swig_acquire_ownership_obj(void *vptr, int own);
     virtual double scalar_value(bool frc_str_conv = false) const
       { return ptr->scalar_value(frc_str_conv); }
 
+#if SWIG_OCTAVE_PREREQ(3,8,0)
+    virtual octave_value map(octave_base_value::unary_mapper_t umap) const
+      { return ptr->map(umap); }
+#endif
+
 #if SWIG_OCTAVE_PREREQ(3,3,52)
     virtual octave_map map_value() const
       { return ptr->map_value(); }