tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithConstraintsTypeArgumentInference2.ts(3,17): error TS2313: Constraint of a type parameter cannot reference any type parameter from the same type parameter list. tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithConstraintsTypeArgumentInference2.ts(11,26): error TS2345: Argument of type 'number' is not assignable to parameter of type 'Date'. Property 'toDateString' is missing in type 'Number'. ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithConstraintsTypeArgumentInference2.ts (2 errors) ==== // Generic call with parameters of T and U, U extends T, no parameter of type U function foo(t: T) { ~~~~~~~~~~~ !!! error TS2313: Constraint of a type parameter cannot reference any type parameter from the same type parameter list. var u: U; return u; } var r = foo(1); // ok var r2 = foo(null); // {} var r3 = foo(new Object()); // {} var r4 = foo(1); // error ~ !!! error TS2345: Argument of type 'number' is not assignable to parameter of type 'Date'. !!! error TS2345: Property 'toDateString' is missing in type 'Number'. var r5 = foo(new Date()); // no error