Type inference: is that a bug? about typescript HOT 3 CLOSED

This is just not something that TS supports. Inference targets have to appear in parameter lists - the "sources" in constraints of other type parameters are ignored. An even simpler repro:

interface Box<T> {
  value: T;
}
function test<T, B extends Box<T>>(a: B) {}
test({ value: 10 });

Arguably, you probably don't want this signature. In situations like this you probably don't want to allow such calls:

new X<number, string, { point: 1, datum: 'a' }>({ point: 1, datum: 'a' })

I'd assume that your E should be strictly { point: number, datum: string } here but your signature allows different subtypes of that.

from typescript.

see #7234 which was not implemented in favor of having people use intersections instead.

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Thank you both, @Andarist @jcalz

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