Free up one bit in TypeFlags

ahejlsberg · ahejlsberg · commit 8f193b40ee3a · 2018-05-26T08:29:30.000-07:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -19934,7 +19934,7 @@ namespace ts {
         // Return true if type might be of the given kind. A union or intersection type might be of a given
         // kind if at least one constituent type is of the given kind.
         function maybeTypeOfKind(type: Type, kind: TypeFlags): boolean {
-            if (type.flags & kind || kind & TypeFlags.GenericMappedType && isGenericMappedType(type)) {
+            if (type.flags & kind & ~TypeFlags.GenericMappedType || kind & TypeFlags.GenericMappedType && isGenericMappedType(type)) {
                 return true;
             }
             if (type.flags & TypeFlags.UnionOrIntersection) {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
@@ -3687,19 +3687,17 @@ namespace ts {
         IndexedAccess           = 1 << 20,  // T[K]
         Conditional             = 1 << 21,  // T extends U ? X : Y
         Substitution            = 1 << 22,  // Type parameter substitution
+        NonPrimitive            = 1 << 23,  // intrinsic object type
         /* @internal */
-        FreshLiteral            = 1 << 23,  // Fresh literal or unique type
+        FreshLiteral            = 1 << 24,  // Fresh literal or unique type
         /* @internal */
-        ContainsWideningType    = 1 << 24,  // Type is or contains undefined or null widening type
+        UnionOfUnitTypes        = 1 << 25,  // Type is union of unit types
         /* @internal */
-        ContainsObjectLiteral   = 1 << 25,  // Type is or contains object literal type
+        ContainsWideningType    = 1 << 26,  // Type is or contains undefined or null widening type
         /* @internal */
-        ContainsAnyFunctionType = 1 << 26,  // Type is or contains the anyFunctionType
-        NonPrimitive            = 1 << 27,  // intrinsic object type
+        ContainsObjectLiteral   = 1 << 27,  // Type is or contains object literal type
         /* @internal */
-        UnionOfUnitTypes        = 1 << 28,  // Type is union of unit types
-        /* @internal */
-        GenericMappedType       = 1 << 29,  // Flag used by maybeTypeOfKind
+        ContainsAnyFunctionType = 1 << 28,  // Type is or contains the anyFunctionType
 
         /* @internal */
         Nullable = Undefined | Null,
@@ -3749,7 +3747,10 @@ namespace ts {
         /* @internal */
         EmptyObject = ContainsAnyFunctionType,
         /* @internal */
-        ConstructionFlags = NonWideningType | Wildcard | EmptyObject
+        ConstructionFlags = NonWideningType | Wildcard | EmptyObject,
+        // The following flag is used for different purposes by maybeTypeOfKind
+        /* @internal */
+        GenericMappedType = ContainsWideningType
     }
 
     export type DestructuringPattern = BindingPattern | ObjectLiteralExpression | ArrayLiteralExpression;

Original file line number	Diff line number	Diff line change
`@@ -19934,7 +19934,7 @@ namespace ts {`
`19934`	`19934`	`// Return true if type might be of the given kind. A union or intersection type might be of a given`
`19935`	`19935`	`// kind if at least one constituent type is of the given kind.`
`19936`	`19936`	`function maybeTypeOfKind(type: Type, kind: TypeFlags): boolean {`
`19937`		`- if (type.flags & kind \|\| kind & TypeFlags.GenericMappedType && isGenericMappedType(type)) {`
	`19937`	`+ if (type.flags & kind & ~TypeFlags.GenericMappedType \|\| kind & TypeFlags.GenericMappedType && isGenericMappedType(type)) {`
`19938`	`19938`	`return true;`
`19939`	`19939`	`}`
`19940`	`19940`	`if (type.flags & TypeFlags.UnionOrIntersection) {`