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// @strict: true
// repro from https://github.com/Microsoft/TypeScript/issues/25675
// The type of `arg` blocks inference but simplifies to T.
function logLength<T extends string, U extends string>(arg: { [K in U]: T }[U]): T {
console.log(arg.length);
return arg;
}
logLength(42); // error
let z;
z = logLength(42); // no error; T is inferred as `any`
function logFirstLength<T extends string[], U extends string>(arg: { [K in U]: T }[U]): T {
console.log(arg[0].length);
return arg;
}
logFirstLength([42]); // error
let zz = [];
zz.push(logLength(42)); // no error; T is inferred as `any`
zz = logFirstLength([42]); // no error; T is inferred as `any[]`
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