Add C++11 alias templates

Doc/Manual/CPlusPlus11.html

@@ -622,20 +622,15 @@ which is equivalent to the old style typedef:
 typedef void (*PFD)(double);  // The old style
 </pre></div>
 
-<p>
-SWIG supports type aliasing.
-</p>
-
 <p>
 The following is an example of an alias template:
 
 <div class="code"><pre>
-template&lt; typename T1, typename T2, int &gt;
+template&lt; typename T1, typename T2, int N &gt;
 class SomeType {
 public:
   T1 a;
   T2 b;
-  int c;
 };
 
 template&lt; typename T2 &gt;
@@ -643,14 +638,14 @@ using TypedefName = SomeType&lt;char*, T2, 5&gt;;
 </pre></div>
 
 <p>
-These are partially supported as SWIG will parse these and identify them, however, they are ignored as they are not added to the type system. A warning such as the following is issued:
+SWIG supports both type aliasing and alias templates.
+However, in order to use an alias template, the <tt>%template</tt> directive must be used:
 </p>
 
-<div class="shell">
-<pre>
-example.i:13: Warning 342: The 'using' keyword in template aliasing is not fully supported yet.
-</pre>
-</div>
+<div class="code"><pre>
+%template(SomeTypeBool) SomeType&lt;char*, bool, 5&gt;;
+%template() TypedefName&lt;bool&gt;;
+</pre></div>
 
 <H3><a name="CPlusPlus11_unrestricted_unions">7.2.17 Unrestricted unions</a></H3>
 

Examples/test-suite/cpp11_template_typedefs.i

@@ -1,56 +1,86 @@
-/* This testcase checks whether SWIG correctly parses alias templates. */
+/* This testcase checks whether SWIG correctly handles alias templates. */
 %module cpp11_template_typedefs
 
-%warnfilter(SWIGWARN_CPP11_ALIAS_TEMPLATE) TypedefName;
-%warnfilter(SWIGWARN_CPP11_ALIAS_TEMPLATE) TypedefNamePtr;
-%warnfilter(SWIGWARN_CPP11_ALIAS_TEMPLATE) MyIntKeyClass;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) PF;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) BucketAllocator1;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) BucketAllocator2;
-
-// This warning should go away when type aliasing is supported
-#pragma SWIG nowarn=SWIGWARN_PARSE_USING_UNDEF // Nothing known about 'p.SomeType< char *,T2,4 >'.
-
 %inline %{
-template< typename T1, typename T2, int >
+
+template<typename T>
+using ptr_t = T*;
+
+namespace ns {
+
+template<typename T1, typename T2, int N>
 class SomeType {
+public:
+  using type1_t = T1;
+  using type2_t = T2;
   T1 a;
   T2 b;
-  int c;
+  constexpr int get_n() { return N; }
 };
 
-// template aliasing
-template< typename T2 >
-using TypedefName = SomeType<char*, T2, 5>;
-template< typename T2 >
-using TypedefNamePtr = SomeType<char*, T2, 4>*;
-
-// type aliasing
-typedef void (*PFD)(double);            // Old style
-using PF = void (*)(double);            // New introduced syntax
-
-
-// use of template aliasing
-template<typename Key,typename Val>
-class MyCPP11Class {
+// Specialization for T1=const char*, T2=bool
+template<int N>
+class SomeType<const char*, bool, N> {
+public:
+  using type1_t = const char*;
+  using type2_t = bool;
+  type1_t a;
+  type2_t b;
+  constexpr int get_n() { return 3 * N; }
 };
-template<typename VAL> using MyIntKeyClass = MyCPP11Class<int,VAL>;
-MyIntKeyClass<char> intchar;
 
-TypedefName<int> alias1(TypedefName<int> a) { return a; }
-TypedefNamePtr<int> alias1(TypedefNamePtr<int> a = nullptr) { return a; }
-%}
+// alias templates
+template<typename T2>
+using TypedefName = SomeType<const char*, T2, 5>;
+template<typename T2>
+using TypedefNamePtr = ptr_t<SomeType<const char*, T2, 4>>;
+
+// alias template that returns T2 for a SomeType<T1,T2,N> class
+template<typename T>
+using T2_of = typename T::type2_t;
+
+T2_of<TypedefName<int>> get_SomeType_b(const SomeType<const char*, int, 5>& x) { return x.b; }
+
+template<typename T>
+T2_of<TypedefName<T>> get_SomeType_b2(const TypedefName<T>& x) { return x.b; }
+
+} // namespace ns
+
+ns::TypedefName<int> create_TypedefName() { return { "hello", 10}; }
+ns::TypedefName<bool> create_TypedefNameBool() { return { "hello", true}; }
+ns::TypedefNamePtr<int> identity(ns::TypedefNamePtr<int> a = nullptr) { return a; }
 
-%inline %{
 typedef double Val;
 template<typename T> struct ListBucket {
 };
 namespace Alloc {
   template<typename T> struct rebind {
-    typedef int other;
+    using other = int;
   };
 }
 
 using BucketAllocator1 = typename Alloc::template rebind<ListBucket<Val>>::other;
 using BucketAllocator2 = typename Alloc::template rebind<::template ListBucket<double>>::other;
+
+BucketAllocator1 get_bucket_allocator1() { return 1; }
+BucketAllocator2 get_bucket_allocator2() { return 2; }
 %}
+
+%immutable ns::SomeType::a;
+
+// %template() directives
+
+%template(SomeTypeInt5) ns::SomeType<const char*, int, 5>;
+%template(SomeTypeInt4) ns::SomeType<const char*, int, 4>;
+%template(SomeTypeBool5) ns::SomeType<const char*, bool, 5>;
+
+%template(ListBucketDouble) ListBucket<Val>;
+%template(RebindListBucketDouble) Alloc::rebind<ListBucket<Val>>;
+
+%template() ptr_t<ns::SomeType<const char*, int, 4>>;
+%template() ns::TypedefName<int>;
+%template() ns::TypedefName<bool>;
+%template() ns::TypedefNamePtr<int>;
+%template() ns::T2_of<ns::TypedefName<int>>;
+
+%template(get_SomeType_b2) ns::get_SomeType_b2<int>;

Examples/test-suite/python/cpp11_template_typedefs_runme.py

@@ -0,0 +1,43 @@
+from cpp11_template_typedefs import *
+
+t = create_TypedefName()
+if type(t).__name__ != "SomeTypeInt5":
+    raise RuntimeError("type(t) is '%s' and should be 'SomeTypeInt5'" % type(t).__name__)
+
+if t.a != "hello":
+    raise RuntimeError("t.a should be 'hello'")
+if t.b != 10:
+    raise RuntimeError("t.b should be 10")
+if t.get_n() != 5:
+    raise RuntimeError("t.get_n() should be 5")
+
+t_bool = create_TypedefNameBool()
+if type(t_bool).__name__ != "SomeTypeBool5":
+    raise RuntimeError("type(t_bool) is '%s' and should be 'SomeTypeBool5'" % type(t_bool).__name__)
+
+if t_bool.a != "hello":
+    raise RuntimeError("t_bool.a should be 'hello'")
+if t_bool.b != True:
+    raise RuntimeError("t_bool.b should be True")
+if t_bool.get_n() != 15:
+    raise RuntimeError("t_bool.get_n() should be 15")
+
+if get_SomeType_b(t) != 10:
+    raise RuntimeError("get_SomeType_b(t) should be 10")
+
+if get_SomeType_b2(t) != 10:
+    raise RuntimeError("get_SomeType_b2(t) should be 10")
+
+t2 = SomeTypeInt4()
+t2.b = 0
+t3 = identity(t2)
+t3.b = 5
+if t2.b != 5:
+    raise RuntimeError("t2.b should be 5")
+
+if get_bucket_allocator1() != 1:
+    raise RuntimeError("bucket_allocator1 should be 1")
+
+# SWIG doesn't handle ::MyClass as a template argument. Skip this test.
+#if get_bucket_allocator2() != 2:
+#    raise RuntimeError("bucket_allocator2 should be 2")

Source/CParse/parser.y

@@ -2910,16 +2910,17 @@ c_declaration   : c_decl {
 		  add_symbols($$);
 		}
                 | TEMPLATE LESSTHAN template_parms GREATERTHAN USING idcolon EQUAL type plain_declarator SEMI {
-		  $$ = new_node("using");
-		  Setattr($$,"name",$6);
+		  /* Convert alias template to a "template" typedef statement */
+		  $$ = new_node("template");
 		  SwigType_push($8,$9.type);
-		  Setattr($$,"uname",$8);
+		  Setattr($$,"type",$8);
+		  Setattr($$,"storage","typedef");
+		  Setattr($$,"name",$6);
+		  Setattr($$,"decl","");
+		  Setattr($$,"templateparms",$3);
+		  Setattr($$,"templatetype","cdecl");
+		  SetFlag($$,"aliastemplate");
 		  add_symbols($$);
-		  SWIG_WARN_NODE_BEGIN($$);
-		  Swig_warning(WARN_CPP11_ALIAS_TEMPLATE, cparse_file, cparse_line, "The 'using' keyword in template aliasing is not fully supported yet.\n");
-		  SWIG_WARN_NODE_END($$);
-
-		  $$ = 0; /* TODO - ignored for now */
 		}
                 ;
 

Source/Modules/lang.cxx

@@ -870,7 +870,7 @@ int Language::cDeclaration(Node *n) {
     } else {
       // Found an unignored templated method that has an empty template instantiation (%template())
       // Ignore it unless it has been %rename'd
-      if (Strncmp(symname, "__dummy_", 8) == 0) {
+      if (Strncmp(symname, "__dummy_", 8) == 0 && Cmp(storage, "typedef") != 0) {
 	SetFlag(n, "feature:ignore");
 	Swig_warning(WARN_LANG_TEMPLATE_METHOD_IGNORE, input_file, line_number,
 	    "%%template() contains no name. Template method ignored: %s\n", Swig_name_decl(n));

Source/Modules/typepass.cxx

@@ -566,6 +566,10 @@ class TypePass:private Dispatcher {
       SwigType_typedef_class(rname);
       Delete(rname);
       /*      SwigType_typedef_class(name); */
+    } else if (Strcmp(ttype, "cdecl") == 0) {
+      String *rname = SwigType_typedef_resolve_all(name);
+      SwigType_typedef_class(rname);
+      Delete(rname);
     }
     return SWIG_OK;
   }