Why implicit type inference only works in an assignment?

Question

I know that using generic in an assignment, a method can implicitly know the type of the return type by looking at the type of the left hand side variable.

Example f

Answer 1

I wouldn't like to claim particular knowledge here, but there's one obvious difference between assignment to a variable, and using the value as a method argument: there's only one possible target in the former case, whether the method is overloaded or not.

Basically it means that you don't need to worry about type inference and overloading / conversions interacting: the inference only happens in the case where you know the one and only target type you're interested in.

This is just a guess though. I've always found Java's type inference interesting - it works the exact opposite way to C# 3, where you can infer the variable's type (so long as it's a local variable).

EDIT: I believe the relevant JLS section is 15.12.2.8:

If the method result occurs in a context where it will be subject to assignment conversion (§5.2) to a type S, then let R be the declared result type of the method [...]

Basically it's the "assignment conversion" bit which is important.