String type matching on index signature

[fongandrew]

As of the latest nightly build (8/31/2015), the following code compiles:

interface Bob { [key: string]: any; }
var x: Bob = "something";

With TSC 1.5.3, I got the error message Index signature is missing in type 'String'. Can someone clarify if this is intended behavior? It seems like it might be (#4074), but it also seems a bit weird to be able to assign a string to what is probably intended to be a basic hash map.

[ahejlsberg]

This is the intended behavior of #4074, the rationale being that any type meets the intended constraint (which basically is none). However, I agree we should probably consider disallowing primitive types since you can't actually add properties to those.