Qian Yu

```ts type MyReturnType = T extends (...args: any[]) => infer R ? R : never ```

```ts type ReplaceAll = From extends '' ? S : S extends `${infer F}${From}${infer L}` ? `${F}${To}${ReplaceAll}` : S ```

```ts type Replace = From extends '' ? S : S extends `${infer F}${From}${infer L}` ? `${F}${To}${L}` : S ```

```ts type MyCapitalize = S extends `${infer F}${infer L}` ? `${Uppercase}${L}` : S ```

```ts type LookUp = T extends { type: U } ? T : never ```

```ts declare function PromiseAll(values: readonly [...T]): Promise ```