Feature/as refactor review (#821)

* Replace dynamicCast with as where does not change behavior (ie not Type derived).
Use free function where scoping is clear.

* Replace uses of dynamicCast with as when there is no difference in behavior.

* Remove the IsXXXX methods from Type.

* Don't have separate smart pointer to store canonicalType on Type.

* Simplify Slang.FilteredMemberRefList.Adjust, such does the cast directly.

* Use free as where appropriate.

* Use free function version of casts where appropriate.

* Fix text in casting.md

* Fix typos in decl-refs.md

* Remove the uses of free function as on RefDecl.
Add 'canAs' to RefDecl as a way to test if a cast is possible.
Moved 'as' into RefDeclBase.

* Use 'is' to test for as cast on smart pointers.
Fix small scope issue.

* * Cache stringType and enumTypeType on the Session
* Make DeclRefType::Create return a RefPtr
* Make casting of result use the *method* .as  (cos using free function would mean objects being wrongly destroyed)
* Make results from createInstance ref'd to avoid possible leaks.

* Fix typo in template parameter for is on RefPtr.

1 files changed, 9 insertions, 7 deletions

diff --git a/source/slang/mangle.cpp b/source/slang/mangle.cpp
index b153cb8dd..1ccd32b07 100644
--- a/source/slang/mangle.cpp
+++ b/source/slang/mangle.cpp
@@ -264,9 +264,11 @@ namespace Slang
 
         // Special case: accessors need some way to distinguish themselves
         // so that a getter/setter/ref-er don't all compile to the same name.
-        if(declRef.as<GetterDecl>())        emitRaw(context, "Ag");
-        if(declRef.as<SetterDecl>())        emitRaw(context, "As");
-        if(declRef.as<RefAccessorDecl>())   emitRaw(context, "Ar");
+        {
+            if (declRef.is<GetterDecl>())        emitRaw(context, "Ag");
+            if (declRef.is<SetterDecl>())        emitRaw(context, "As");
+            if (declRef.is<RefAccessorDecl>())   emitRaw(context, "Ar");
+        }
 
         // Are we the "inner" declaration beneath a generic decl?
         if(parentGenericDeclRef && (parentGenericDeclRef.getDecl()->inner.Ptr() == declRef.getDecl()))
@@ -294,15 +296,15 @@ namespace Slang
                 UInt genericParameterCount = 0;
                 for( auto mm : getMembers(parentGenericDeclRef) )
                 {
-                    if(mm.as<GenericTypeParamDecl>())
+                    if(as<GenericTypeParamDecl>(mm))
                     {
                         genericParameterCount++;
                     }
-                    else if(mm.as<GenericValueParamDecl>())
+                    else if(as<GenericValueParamDecl>(mm))
                     {
                         genericParameterCount++;
                     }
-                    else if(mm.as<GenericTypeConstraintDecl>())
+                    else if(as<GenericTypeConstraintDecl>(mm))
                     {
                         genericParameterCount++;
                     }
@@ -358,7 +360,7 @@ namespace Slang
 
             // Don't print result type for an initializer/constructor,
             // since it is implicit in the qualified name.
-            if (!callableDeclRef.as<ConstructorDecl>())
+            if (!callableDeclRef.is<ConstructorDecl>())
             {
                 emitType(context, GetResultType(callableDeclRef));
             }