//// [ambiguousOverloadResolution.ts] class A { } class B extends A { x: number; } declare function f(p: A, q: B): number; declare function f(p: B, q: A): string; var x: B; var t: number = f(x, x); // Not an error //// [ambiguousOverloadResolution.js] var __extends = this.__extends || function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; function __() { this.constructor = d; } __.prototype = b.prototype; d.prototype = new __(); }; var A = (function () { function A() { } return A; })(); var B = (function (_super) { __extends(B, _super); function B() { _super.apply(this, arguments); } return B; })(A); var x; var t = f(x, x); // Not an error