cc @ahejlsberg **TypeScript Version:** master <!-- Search terms you tried before logging this (so others can find this issue more easily) --> **Search Terms:** **Code** ```ts type A<T extends string[]> = T extends Array<infer U> ? Record<U, {}> : never; ``` **Expected behavior:** pass **Actual behavior:** ``` $ node built/local/tsc.js --noEmit index.ts index.ts(1,64): error TS2344: Type 'U' does not satisfy the constraint 'string'. ``` **Playground Link:** <!-- A link to a TypeScript Playground "Share" link which demonstrates this behavior --> **Related Issues:**