From 04f46ff87d3eb6803e2f07dea5f28ff1f88d8afd Mon Sep 17 00:00:00 2001
From: Walter Bright <WalterBright@users.noreply.github.com>
Date: Tue, 1 Aug 2023 02:48:34 -0700
Subject: [PATCH] remove some dyncast calls (#15488)

---
 compiler/src/dmd/declaration.d |  2 +-
 compiler/src/dmd/dinterpret.d  |  2 +-
 compiler/src/dmd/dscope.d      |  2 +-
 compiler/src/dmd/dsymbol.d     |  4 ++--
 compiler/src/dmd/func.d        |  4 ++--
 compiler/src/dmd/nogc.d        |  6 ++++--
 compiler/src/dmd/typesem.d     | 10 ++++------
 7 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/compiler/src/dmd/declaration.d b/compiler/src/dmd/declaration.d
index 9db57ce0d9..6cfb53dd1c 100644
--- a/compiler/src/dmd/declaration.d
+++ b/compiler/src/dmd/declaration.d
@@ -626,7 +626,7 @@ extern (C++) final class TupleDeclaration : Declaration
             for (size_t i = 0; i < objects.length; i++)
             {
                 RootObject o = (*objects)[i];
-                if (o.dyncast() != DYNCAST.type)
+                if (!o.isType())
                 {
                     //printf("\tnot[%d], %p, %d\n", i, o, o.dyncast());
                     return null;
diff --git a/compiler/src/dmd/dinterpret.d b/compiler/src/dmd/dinterpret.d
index 228245db57..59483511f6 100644
--- a/compiler/src/dmd/dinterpret.d
+++ b/compiler/src/dmd/dinterpret.d
@@ -7706,7 +7706,7 @@ private void removeHookTraceImpl(ref CallExp ce, ref FuncDeclaration fd)
     // Get the Hook from the second template parameter
     TemplateInstance templateInstance = fd.parent.isTemplateInstance;
     RootObject hook = (*templateInstance.tiargs)[1];
-    assert(hook.dyncast() == DYNCAST.dsymbol, "Expected _d_HookTraceImpl's second template parameter to be an alias to the hook!");
+    assert(hook.isDsymbol(), "Expected _d_HookTraceImpl's second template parameter to be an alias to the hook!");
     fd = (cast(Dsymbol)hook).isFuncDeclaration;
 
     // Remove the first three trace parameters
diff --git a/compiler/src/dmd/dscope.d b/compiler/src/dmd/dscope.d
index dc4986282b..c2c0628f5e 100644
--- a/compiler/src/dmd/dscope.d
+++ b/compiler/src/dmd/dscope.d
@@ -168,7 +168,7 @@ extern (C++) struct Scope
         sc.minst = _module;
         sc.scopesym = new ScopeDsymbol();
         sc.scopesym.symtab = new DsymbolTable();
-	sc.eSink = eSink;
+        sc.eSink = eSink;
         // Add top level package as member of this global scope
         Dsymbol m = _module;
         while (m.parent)
diff --git a/compiler/src/dmd/dsymbol.d b/compiler/src/dmd/dsymbol.d
index 8ebdc03710..0fa4dbcfa5 100644
--- a/compiler/src/dmd/dsymbol.d
+++ b/compiler/src/dmd/dsymbol.d
@@ -353,9 +353,9 @@ extern (C++) class Dsymbol : ASTNode
     {
         if (this == o)
             return true;
-        if (o.dyncast() != DYNCAST.dsymbol)
+        const s = o.isDsymbol();
+        if (!s)
             return false;
-        auto s = cast(Dsymbol)o;
         // Overload sets don't have an ident
         // Function-local declarations may have identical names
         // if they are declared in different scopes
diff --git a/compiler/src/dmd/func.d b/compiler/src/dmd/func.d
index d58b11e602..c963a470a3 100644
--- a/compiler/src/dmd/func.d
+++ b/compiler/src/dmd/func.d
@@ -4708,9 +4708,9 @@ void errorSupplementalInferredAttr(FuncDeclaration fd, int maxDepth, bool deprec
                     s.arg0 ? s.arg0.toChars() : "", s.arg1 ? s.arg1.toChars() : "", s.arg2 ? s.arg2.toChars() : "");
             }
         }
-        else if (s.arg0.dyncast() == DYNCAST.dsymbol)
+        else if (auto sa = s.arg0.isDsymbol())
         {
-            if (FuncDeclaration fd2 = (cast(Dsymbol) s.arg0).isFuncDeclaration())
+            if (FuncDeclaration fd2 = sa.isFuncDeclaration())
             {
                 if (maxDepth > 0)
                 {
diff --git a/compiler/src/dmd/nogc.d b/compiler/src/dmd/nogc.d
index 18cf3180a3..01a6832a97 100644
--- a/compiler/src/dmd/nogc.d
+++ b/compiler/src/dmd/nogc.d
@@ -19,6 +19,7 @@ import dmd.aggregate;
 import dmd.astenums;
 import dmd.declaration;
 import dmd.dscope;
+import dmd.dtemplate : isDsymbol;
 import dmd.errors;
 import dmd.expression;
 import dmd.func;
@@ -263,6 +264,7 @@ private FuncDeclaration stripHookTraceImpl(FuncDeclaration fd)
     // Get the Hook from the second template parameter
     auto templateInstance = fd.parent.isTemplateInstance;
     RootObject hook = (*templateInstance.tiargs)[1];
-    assert(hook.dyncast() == DYNCAST.dsymbol, "Expected _d_HookTraceImpl's second template parameter to be an alias to the hook!");
-    return (cast(Dsymbol)hook).isFuncDeclaration;
+    Dsymbol s = hook.isDsymbol();
+    assert(s, "Expected _d_HookTraceImpl's second template parameter to be an alias to the hook!");
+    return s.isFuncDeclaration;
 }
diff --git a/compiler/src/dmd/typesem.d b/compiler/src/dmd/typesem.d
index a044a4fd7e..a80aa80a89 100644
--- a/compiler/src/dmd/typesem.d
+++ b/compiler/src/dmd/typesem.d
@@ -530,12 +530,10 @@ extern(C++) Type typeSemantic(Type type, const ref Loc loc, Scope* sc)
             }
 
             RootObject o = (*tup.objects)[cast(size_t)d];
-            if (o.dyncast() != DYNCAST.type)
-            {
-                .error(loc, "`%s` is not a type", mtype.toChars());
-                return error();
-            }
-            return (cast(Type)o).addMod(mtype.mod);
+            if (auto tt = o.isType())
+                return tt.addMod(mtype.mod);
+            .error(loc, "`%s` is not a type", mtype.toChars());
+            return error();
         }
 
         if (t && t.ty == Terror)