为啥两个type不一样？

Question

为啥两个type不一样

Answer 1

因为Distributive Conditional Types

// 所以 type res2 = MyExclude<b, a> 相当于
type res2 = ('a' extends a ? never : 'a') | ('b' extends a ? never : 'b') | ('c' extends a ? never : 'c')