Merge pull request #6571 from yazd/issue16083

Fix issue 16083 - AliasSeq loses type of enums that have the same value

src/ddmd/dtemplate.d

@@ -260,7 +260,12 @@ private bool match(RootObject o1, RootObject o2)
             printf("\te1 = %s '%s' %s\n", e1.type.toChars(), Token.toChars(e1.op), e1.toChars());
             printf("\te2 = %s '%s' %s\n", e2.type.toChars(), Token.toChars(e2.op), e2.toChars());
         }
-        if (!e1.equals(e2))
+
+        // two expressions can be equal although they do not have the same
+        // type; that happens when they have the same value. So check type
+        // as well as expression equality to ensure templates are properly
+        // matched.
+        if (!e1.type.equals(e2.type) || !e1.equals(e2))
             goto Lnomatch;
 
         goto Lmatch;

test/compilable/test16083.d

@@ -0,0 +1,15 @@
+template Alias(Stuff...)
+{
+    alias Alias = Stuff;
+}
+
+enum A { a = 0 }
+enum B { b = 0 }
+
+enum C { c = "abc" }
+enum D { d = "abc" }
+
+static assert(is(typeof(Alias!(A.a)[0]) == A));
+static assert(is(typeof(Alias!(B.b)[0]) == B));
+static assert(is(typeof(Alias!(C.c)[0]) == C));
+static assert(is(typeof(Alias!(D.d)[0]) == D));