From 525426911cecb9a228c62e9e26ed9e7e8a3910e0 Mon Sep 17 00:00:00 2001
From: William S Fulton <wsf@fultondesigns.co.uk>
Date: Fri, 21 Jul 2023 19:28:27 +0100
Subject: [PATCH] C++11 using declarations for inheriting implicit base
 templated constructors

Testcase - compiles given previous commit, but needs more work!
---
 .../cpp11_director_using_constructor.i        |  4 +++
 Examples/test-suite/cpp11_using_constructor.i | 35 ++++++++++++++++++-
 .../java/cpp11_using_constructor_runme.java   |  5 +++
 3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/Examples/test-suite/cpp11_director_using_constructor.i b/Examples/test-suite/cpp11_director_using_constructor.i
index f76624969..91d25711c 100644
--- a/Examples/test-suite/cpp11_director_using_constructor.i
+++ b/Examples/test-suite/cpp11_director_using_constructor.i
@@ -5,4 +5,8 @@
 
 %feature("director");
 
+%warnfilter(SWIGWARN_LANG_DIRECTOR_ABSTRACT) TemplateConstructor1Derived;
+%warnfilter(SWIGWARN_LANG_DIRECTOR_ABSTRACT) TemplateConstructor2Base;
+%warnfilter(SWIGWARN_LANG_DIRECTOR_ABSTRACT) TemplateConstructor2Derived;
+
 %include "cpp11_using_constructor.i"
diff --git a/Examples/test-suite/cpp11_using_constructor.i b/Examples/test-suite/cpp11_using_constructor.i
index 9772f7086..6c3e793e3 100644
--- a/Examples/test-suite/cpp11_using_constructor.i
+++ b/Examples/test-suite/cpp11_using_constructor.i
@@ -423,7 +423,6 @@ struct TemplPublicBase6 {
 #endif
   virtual void meth() {}
 };
-
 %}
 
 %template(TemplPublicBase1Int) TemplPublicBase1<int>;
@@ -472,3 +471,37 @@ struct TemplPublicDerived6 : TemplPublicBase6<T> {
 %template(TemplPublicDerived4Int) TemplPublicDerived4<int>;
 %template(TemplPublicDerived5Int) TemplPublicDerived5<int>;
 %template(TemplPublicDerived6Int) TemplPublicDerived6<int>;
+
+
+// Templated constructors
+%inline %{
+struct TemplateConstructor1Base {
+  virtual ~TemplateConstructor1Base() {}
+  // No implicit constructor
+  template <typename T> TemplateConstructor1Base(const T &t, const char *s) {}
+  virtual void meth() {}
+};
+%}
+
+%template(TemplateConstructor1Base) TemplateConstructor1Base::TemplateConstructor1Base<int>;
+
+%inline %{
+struct TemplateConstructor1Derived : TemplateConstructor1Base {
+  using TemplateConstructor1Base::TemplateConstructor1Base;
+  using TemplateConstructor1Base::meth;
+};
+%}
+
+// TODO: Missing constructors, below probably ought to work using instantiation as follows:
+//%template(TemplateConstructor1Derived) TemplateConstructor1Derived::TemplateConstructor1Derived<int>;
+
+%{
+void tester() {
+  TemplateConstructor1Derived tc = TemplateConstructor1Derived(123, "hi");
+  tc.meth();
+  // Note not valid c++:
+  // TemplateConstructor1Derived tc2 = TemplateConstructor1Derived::TemplateConstructor1Derived<int>(123, "hi");
+}
+%}
+
+// Note that templated methods also not working with using declarations for inheriting from base templated methods
diff --git a/Examples/test-suite/java/cpp11_using_constructor_runme.java b/Examples/test-suite/java/cpp11_using_constructor_runme.java
index eed27693f..b6ccc305a 100644
--- a/Examples/test-suite/java/cpp11_using_constructor_runme.java
+++ b/Examples/test-suite/java/cpp11_using_constructor_runme.java
@@ -127,5 +127,10 @@ public class cpp11_using_constructor_runme {
     new TemplPublicDerived5Int().meth();
     new TemplPublicDerived6Int(0, "hi").meth();
     new TemplPublicDerived6Int().meth();
+
+    // Templated constructors
+    new TemplateConstructor1Base(0, "hi").meth();
+    // TODO: missing constructor...
+    // new TemplateConstructor1Derived(0, "hi").meth();
   }
 }