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Tuple to Union

介绍​

实现一个TupleToUnion<T>泛型, 涵盖元组的值转换为联合类型

For example

ts
type Arr = ['1', '2', '3']
const a: TupleToUnion<Arr> // expected to be '1' | '2' | '3'
ts
type Arr = ['1', '2', '3']
const a: TupleToUnion<Arr> // expected to be '1' | '2' | '3'
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起点​

ts
/* _____________ Your Code Here _____________ */
 
type TupleToUnion<T> = any
 
/* _____________ Test Cases _____________ */
type cases = [
  Expect<Equal<TupleToUnion<[123, '456', true]>, 123 | '456' | true>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<TupleToUnion<[123]>, 123>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
]
ts
/* _____________ Your Code Here _____________ */
 
type TupleToUnion<T> = any
 
/* _____________ Test Cases _____________ */
type cases = [
  Expect<Equal<TupleToUnion<[123, '456', true]>, 123 | '456' | true>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
  Expect<Equal<TupleToUnion<[123]>, 123>>,
Type 'false' does not satisfy the constraint 'true'.2344Type 'false' does not satisfy the constraint 'true'.
]
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解决方案​

Spoiler warning // Click to reveal answer
ts
// 方案1
type TupleToUnion<T extends any[]> = T[number]
 
ts
// 方案1
type TupleToUnion<T extends any[]> = T[number]
 
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