tests/cases/compiler/overloadOnConstNoAnyImplementation.ts(1,28): error TS2382: Specialized overload signature is not assignable to any non-specialized signature. tests/cases/compiler/overloadOnConstNoAnyImplementation.ts(2,28): error TS2382: Specialized overload signature is not assignable to any non-specialized signature. tests/cases/compiler/overloadOnConstNoAnyImplementation.ts(9,8): error TS2345: Argument of type 'number' is not assignable to parameter of type 'string'. tests/cases/compiler/overloadOnConstNoAnyImplementation.ts(14,7): error TS2381: A signature with an implementation cannot use a string literal type. ==== tests/cases/compiler/overloadOnConstNoAnyImplementation.ts (4 errors) ==== function x1(a: number, cb: (x: 'hi') => number); ~~~~~~~~~~~~~~~~~~~ !!! error TS2382: Specialized overload signature is not assignable to any non-specialized signature. function x1(a: number, cb: (x: 'bye') => number); ~~~~~~~~~~~~~~~~~~~~ !!! error TS2382: Specialized overload signature is not assignable to any non-specialized signature. function x1(a: number, cb: (x: string) => number) { cb('hi'); cb('bye'); var hm = 'hm'; cb(hm); cb('uh'); cb(1); // error ~ !!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'string'. } var cb: (number) => number = (x: number) => 1; x1(1, cb); x1(1, (x: 'hi') => 1); // error ~~~~~~~~~~~~~~ !!! error TS2381: A signature with an implementation cannot use a string literal type. x1(1, (x: string) => 1);