16 lines
802 B
Plaintext
16 lines
802 B
Plaintext
==== tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSupertype.ts (1 errors) ====
|
|
// subtype checks use the apparent type of the target type
|
|
// S is a subtype of a type T, and T is a supertype of S, if one of the following is true, where S' denotes the apparent type (section 3.8.1) of S:
|
|
|
|
class Base {
|
|
x: string;
|
|
}
|
|
|
|
// is String (S) a subtype of U extends String (T)? Would only be true if we used the apparent type of U (T)
|
|
class Derived<U extends String> extends Base { // error
|
|
~~~~~~~
|
|
!!! error TS2416: Class 'Derived<U>' incorrectly extends base class 'Base':
|
|
!!! error TS2416: Types of property 'x' are incompatible:
|
|
!!! error TS2416: Type 'U' is not assignable to type 'string'.
|
|
x: U;
|
|
} |