fix(to_cpp1): define type-scope object alias with wildcard type inline

Author: JohelEGP

regression-tests/pure2-bugfix-for-ufcs-name-lookup.cpp2

@@ -12,10 +12,10 @@ ns: namespace = {
 f: (_) -> int == 1;
 } // namespace ns
 
-// v: @struct type = {
-//   f :== :(_) 0; // Pending on #706.
-//   g: (i) i.f();
-// }
+v: @struct type = {
+  f :== :(_) 0;
+  g: (i) i.f();
+}
 
 main: () = {
   {

regression-tests/pure2-type-and-namespace-aliases.cpp2

@@ -33,3 +33,25 @@ main: () = {
     myfunc2 :== myfunc;
     myfunc2();
 }
+
+myclass5: type == myclass4;
+
+myclass3: @struct type = {
+    // Defined inline.
+    i0 :== :std::array = (0);
+    i1 :== i0;
+    i3: _ == i0;
+    i7 :== :() 0;
+
+    // Defined out of line.
+    o2: myclass3 == myclass3();
+    o4: myclass3 == o2;
+    o5: myclass4 == myclass4();
+    o6: myclass5 == myclass5();
+}
+
+myclass4: @struct type = { }
+
+myclass6: @struct <T: type> type = {
+    v: <U> _ requires true == 0;
+}

regression-tests/test-results/pure2-bugfix-for-ufcs-name-lookup.cpp

@@ -22,6 +22,8 @@ namespace ns {
 
 }
 
+class v;
+  
 
 //=== Cpp2 type definitions and function declarations ===========================
 
@@ -41,10 +43,10 @@ namespace ns {
 [[nodiscard]] constexpr auto f([[maybe_unused]] auto const& unnamed_param_1) -> int;
 } // namespace ns
 
-// v: @struct type = {
-//   f :== :(_) 0; // Pending on #706.
-//   g: (i) i.f();
-// }
+class v {
+  public: static constexpr auto f = []([[maybe_unused]] auto const& unnamed_param_1) mutable -> auto { return 0; };
+  public: [[nodiscard]] static auto g(auto const& i) -> auto;
+};
 
 auto main() -> int;
 
@@ -63,6 +65,9 @@ namespace ns {
 [[nodiscard]] constexpr auto f([[maybe_unused]] auto const& unnamed_param_1) -> int { return 1;  }
 }
 
+#line 17 "pure2-bugfix-for-ufcs-name-lookup.cpp2"
+  [[nodiscard]] auto v::g(auto const& i) -> auto { return CPP2_UFCS(f)(i);  }
+
 #line 20 "pure2-bugfix-for-ufcs-name-lookup.cpp2"
 auto main() -> int{
   {

regression-tests/test-results/pure2-type-and-namespace-aliases.cpp

@@ -21,6 +21,16 @@ class myclass;
 template<typename T> class myclass2;
 
 
+#line 39 "pure2-type-and-namespace-aliases.cpp2"
+class myclass3;
+    
+
+#line 53 "pure2-type-and-namespace-aliases.cpp2"
+class myclass4;
+
+template<typename T> class myclass6;
+    
+
 //=== Cpp2 type definitions and function declarations ===========================
 
 #line 1 "pure2-type-and-namespace-aliases.cpp2"
@@ -60,6 +70,31 @@ template<typename T> class myclass2 {
 
 auto main() -> int;
 
+#line 37 "pure2-type-and-namespace-aliases.cpp2"
+using myclass5 = myclass4;
+
+class myclass3 {
+    // Defined inline.
+    public: static constexpr auto i0 = std::array{0};
+    public: static constexpr auto i1 = i0;
+    public: static constexpr auto i3 = i0;
+    public: static constexpr auto i7 = []() mutable -> auto { return 0; };
+
+    // Defined out of line.
+    public: static const myclass3 o2;
+    public: static const myclass3 o4;
+    public: static const myclass4 o5;
+    public: static const myclass5 o6;
+};
+
+class myclass4 {};
+
+template<typename T> class myclass6 {
+#line 56 "pure2-type-and-namespace-aliases.cpp2"
+    public: template<typename U> 
+CPP2_REQUIRES_ (true) static constexpr auto v = 0;
+};
+
 //=== Cpp2 function definitions =================================================
 
 #line 1 "pure2-type-and-namespace-aliases.cpp2"
@@ -94,3 +129,9 @@ auto main() -> int{
     myfunc2();
 }
 
+#line 47 "pure2-type-and-namespace-aliases.cpp2"
+    inline CPP2_CONSTEXPR myclass3 myclass3::o2 = myclass3();
+    inline CPP2_CONSTEXPR myclass3 myclass3::o4 = o2;
+    inline CPP2_CONSTEXPR myclass4 myclass3::o5 = myclass4();
+    inline CPP2_CONSTEXPR myclass5 myclass3::o6 = myclass5();
+

source/to_cpp1.h

@@ -4639,7 +4639,7 @@ class cppfront
             );
         }
         else {
-            emit(*n.parameters, false, false, generating_postfix_inc_dec); 
+            emit(*n.parameters, false, false, generating_postfix_inc_dec);
         }
 
         //  For an anonymous function, the emitted lambda is 'constexpr' or 'mutable'
@@ -5378,8 +5378,18 @@ class cppfront
             auto& a = std::get<declaration_node::an_alias>(n.type);
             assert(a);
 
+            //  Helper for aliases that emit as a defining declaration.
+            auto const type_scope_object_alias_emits_in_phase_1_only = [&]() {
+                assert(
+                    n.parent_is_type()
+                    && n.is_object_alias()
+                );
+                return !a->type_id
+                       || a->type_id->is_wildcard();
+            };
+
             //  Namespace-scope aliases are emitted in phase 1,
-            //  type-scope object aliases in both phases 1 and 2, and
+            //  type-scope object aliases is emitted in phase 1 and maybe 2, and
             //  function-scope aliases in phase 2
             if (
                 (
@@ -5391,6 +5401,7 @@ class cppfront
                     n.parent_is_type()
                     && n.is_object_alias()
                     && printer.get_phase() == printer.phase2_func_defs
+                    && !type_scope_object_alias_emits_in_phase_1_only()
                     )
                 ||
                 (
@@ -5465,21 +5476,34 @@ class cppfront
                 //  Handle object aliases:
                 //      - at function scope, it's const&
                 //      - at namespace scope, it's inline constexpr
-                //      - at type scope, it's also inline constexpr but see note (*) below
+                //      - at type scope, it's also static constexpr but see note (*) below
                 else if (a->is_object_alias())
                 {
                     auto type = std::string{"auto"};
                     if (a->type_id) {
                         type = print_to_string(*a->type_id);
                     }
 
-                    //  (*) If this is at type scope, Cpp1 requires an out-of-line declaration dance
-                    //  for some cases to work - see https://stackoverflow.com/questions/11928089/
                     if (n.parent_is_type())
                     {
                         assert (n.parent_declaration->name());
 
-                        if (printer.get_phase() == printer.phase1_type_defs_func_decls) {
+                        if (type_scope_object_alias_emits_in_phase_1_only()) {
+                            if (printer.get_phase() == printer.phase1_type_defs_func_decls) {
+                                printer.print_cpp2(
+                                    "static constexpr "
+                                        + type + " "
+                                        + print_to_string(*n.identifier)
+                                        + " = "
+                                        + print_to_string( *std::get<alias_node::an_object>(a->initializer) )
+                                        + ";\n",
+                                    n.position()
+                                );
+                            }
+                        }
+                        //  At type scope, Cpp1 requires an out-of-line declaration dance
+                        //  for some cases to work - see https://stackoverflow.com/questions/11928089/
+                        else if (printer.get_phase() == printer.phase1_type_defs_func_decls) {
                             printer.print_cpp2(
                                 "static const "
                                     + type + " "
@@ -5663,7 +5687,10 @@ class cppfront
 
         //  In class definitions, emit the explicit access specifier if there
         //  is one, or default to private for data and public for functions
-        if (printer.get_phase() == printer.phase1_type_defs_func_decls)
+        if (
+            printer.get_phase() == printer.phase1_type_defs_func_decls
+            && n.identifier
+            )
         {
             if (!n.is_default_access()) {
                 assert (is_in_type);