Enhance %extend to extend a class with template constructors

CHANGES.current

@@ -7,6 +7,19 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 3.0.12 (in progress)
 ============================
 
+2017-01-24: wsfulton
+            Enhance %extend to extend a class with template constructors, eg:
+
+              struct Foo {
+                %extend {
+                  template<typename T>
+                  Foo(int a, T b) {
+                    ...
+                  }
+                }
+              };
+              %template(Foo) Foo::Foo<double>;
+
 2017-01-22: wsfulton
             Issue #876 Enhance %extend to extend a class with template methods, eg:
 
@@ -20,6 +33,8 @@ Version 3.0.12 (in progress)
               };
               %template(do_stuff_inst) Foo::do_stuff<double>;
 
+              Similarly for static template methods.
+
 2017-01-22: kwwette
             [Octave] add support for version 4.2
             - The Octave API now uses some C++11 features. It is recommended to use

Examples/test-suite/extend_template_method.i

@@ -6,6 +6,7 @@
 namespace Space {
 class ExtendMe {
 public:
+  ExtendMe() {}
   template <typename T>
   T do_stuff_impl(int a, T b, double d) {
     return b;
@@ -24,7 +25,14 @@ public:
     return $self->do_stuff_impl(0, b, 4.0);
   }
   template<typename T>
-  static T static_method(T t) { return t; }
+  static T static_method(T t) {
+    return t;
+  }
+  template<typename T>
+  ExtendMe(T x) {
+    Space::ExtendMe *em = new Space::ExtendMe();
+    return em;
+  }
 }
 %template(do_stuff_double) Space::ExtendMe::do_stuff<double>;
 %template(do_stuff_string) Space::ExtendMe::do_stuff<std::string>;
@@ -34,11 +42,14 @@ public:
 
 %template(static_method) Space::ExtendMe::static_method<int>;
 
+%template(ExtendMe) Space::ExtendMe::ExtendMe<int>;
+
 %inline %{
 namespace Space {
 template<typename X>
 class TemplateExtendMe {
 public:
+  TemplateExtendMe() {}
   template <typename T>
   T template_stuff_impl(X a, T b, double d) {
     return b;
@@ -57,7 +68,14 @@ public:
     return $self->template_stuff_impl(0, b, 4.0);
   }
   template<typename T>
-  static T static_template_method(T t) { return t; }
+  static T static_template_method(T t) {
+    return t;
+  }
+  template<typename T>
+  TemplateExtendMe(T x) {
+    Space::TemplateExtendMe<X> *em = new Space::TemplateExtendMe<X>();
+    return em;
+  }
 
 %template(do_template_stuff_double) do_template_stuff<double>;
 %template(do_template_stuff_string) do_template_stuff<std::string>;
@@ -66,6 +84,8 @@ public:
 %template(do_template_overloaded_stuff) do_template_overloaded_stuff<double>;
 
 %template(static_template_method) static_template_method<int>;
+
+%template(TemplateExtendMe) Space::TemplateExtendMe::TemplateExtendMe<int>;
 }
 
 %template(TemplateExtend) Space::TemplateExtendMe<int>;

Examples/test-suite/java/extend_template_method_runme.java

@@ -34,6 +34,7 @@ public class extend_template_method_runme {
       }
       if (ExtendMe.static_method(123) != 123)
         throw new RuntimeException("static_method failed");
+      ExtendMe em2 = new ExtendMe(123);
     }
     {
       TemplateExtend em = new TemplateExtend();
@@ -56,6 +57,7 @@ public class extend_template_method_runme {
       }
       if (TemplateExtend.static_template_method(123) != 123)
         throw new RuntimeException("static_template_method failed");
+      TemplateExtend em2 = new TemplateExtend(123);
     }
   }
 }

Examples/test-suite/python/extend_template_method_runme.py

@@ -18,7 +18,9 @@ if ret_string != "hello there":
     raise RuntimeError("string failed " + ret_string)
 
 if ExtendMe.static_method(123) != 123:
-  raise RuntimeError("static_method failed");
+  raise RuntimeError("static_method failed")
+
+em2 = ExtendMe(123)
 
 em = TemplateExtend()
 
@@ -38,4 +40,6 @@ if ret_string != "hello there":
     raise RuntimeError("string failed " + ret_string)
 
 if TemplateExtend.static_template_method(123) != 123:
-  raise RuntimeError("static_template_method failed");
+  raise RuntimeError("static_template_method failed")
+
+em2 = TemplateExtend(123)

Source/Modules/lang.cxx

@@ -2791,7 +2791,9 @@ int Language::constructorHandler(Node *n) {
     Setattr(n, "handled_as_constructor", "1");
   }
 
-  Swig_ConstructorToFunction(n, NSpace, ClassType, none_comparison, director_ctor, CPlusPlus, Getattr(n, "template") ? 0 : Extend, DirectorClassName);
+  int extendmember = GetFlag(n, "isextendmember") ? Extend : 0;
+  int flags = Getattr(n, "template") ? extendmember : Extend;
+  Swig_ConstructorToFunction(n, NSpace, ClassType, none_comparison, director_ctor, CPlusPlus, flags, DirectorClassName);
   Setattr(n, "sym:name", mrename);
   functionWrapper(n);
   Delete(mrename);