我不太知道如何表達(dá)這個(gè)問(wèn)題，但我偶然發(fā)現(xiàn)了一個(gè)特殊的問(wèn)題。我試圖Thingy通過(guò)使用foo類型為Kind.interface AKind {    kind: 'A';}interface BKind {    kind: 'B';}interface CKind {    kind: 'C';}type Kind = AKind | BKind | CKind;type ExCThingy = {    foo: Exclude<Kind, CKind>,    something: 'test';}type CThingy = {    foo: CKind,    somethingelse: 'test2';}type Foo = {    foo: Kind}function DoSomething(args: ExCThingy | CThingy) {    function isCThingy(args: ExCThingy | CThingy): args is CThingy {        return args.foo.kind === 'C';    }    if (isCThingy(args)) {        //Do C thing        return;    }    //else Do ExC thing    return;}const a: AKind = {    kind: 'A',}const b: BKind = {    kind: 'B',}const c: CKind = {    kind: 'C',}const fooArray: Foo[] = [{    foo: a,},{    foo: b,},{    foo: c,    }];fooArray.map(e => DoSomething({    foo: e.foo,    something: 'test',    somethingelse: 'test2'}));ts 編譯器抱怨：Argument of type '{ foo: Kind; something: "test"; somethingelse: "test2"; }' is not assignable to parameter of type 'ExCThingy | CThingy'.  Type '{ foo: Kind; something: "test"; somethingelse: "test2"; }' is not assignable to type 'CThingy'.    Types of property 'foo' are incompatible.      Type 'Kind' is not assignable to type 'CKind'.        Type 'AKind' is not assignable to type 'CKind'.          Types of property 'kind' are incompatible.            Type '"A"' is not assignable to type '"C"'.(2345)