tests/cases/compiler/typeParameterArgumentEquivalence3.ts(4,5): error TS2322: Type '(item: any) => boolean' is not assignable to type '(item: any) => T'.
  Type 'boolean' is not assignable to type 'T'.
    'T' could be instantiated with an arbitrary type which could be unrelated to 'boolean'.
tests/cases/compiler/typeParameterArgumentEquivalence3.ts(5,5): error TS2322: Type '(item: any) => T' is not assignable to type '(item: any) => boolean'.
  Type 'T' is not assignable to type 'boolean'.


==== tests/cases/compiler/typeParameterArgumentEquivalence3.ts (2 errors) ====
    function foo<T,U>() {
        var x: (item) => T;
        var y: (item) => boolean;
        x = y;  // Should be an error
        ~
!!! error TS2322: Type '(item: any) => boolean' is not assignable to type '(item: any) => T'.
!!! error TS2322:   Type 'boolean' is not assignable to type 'T'.
!!! error TS2322:     'T' could be instantiated with an arbitrary type which could be unrelated to 'boolean'.
        y = x;  // Shound be an error
        ~
!!! error TS2322: Type '(item: any) => T' is not assignable to type '(item: any) => boolean'.
!!! error TS2322:   Type 'T' is not assignable to type 'boolean'.
!!! related TS2208 tests/cases/compiler/typeParameterArgumentEquivalence3.ts:1:14: This type parameter might need an `extends boolean` constraint.
    }
    