Function createBackreferenceMapper

test/fixtures/snapshot/typescript.js:63322–63324

* Maps forward-references to later types parameters to the empty object type. * This is used during inference when instantiating type parameter defaults.

(context, index)

         * This is used during inference when instantiating type parameter defaults.
         */
        function createBackreferenceMapper(context, index) {
            return makeFunctionTypeMapper(function (t) { return ts.findIndex(context.inferences, function (info) { return info.typeParameter === t; }) >= index ? unknownType : t; });
        }
        function combineTypeMappers(mapper1, mapper2) {
            return mapper1 ? makeCompositeTypeMapper(3 /* TypeMapKind.Composite */, mapper1, mapper2) : mapper2;
        }