Assignment to immutable argument: diagnostic tweak

[estebank]

Re #46659.

[rust-highfive]

r? @petrochenkov

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[petrochenkov]

Shouldn't this message say "argument" instead of "variable" as well?

[petrochenkov]

@bors r+

[bors]

📌 Commit 90bc98c has been approved by petrochenkov

[petrochenkov]

So
much
vertical
space.

Now every time I see stuff like this I'm rewording it with is expressions in my head.

let is_arg = place is Place::Local(local) && self.mir.local_kind(*local) is LocalKind::Arg;

[leoyvens]

@petrochenkov To be fair this is just:

let is_arg = match place {
    Place::Local(local) => self.mir.local_kind(*local) == LocalKind::Arg,
    _ => false
};

I think if let is overused and match is better in many cases.

[estebank]

True, I usually revert to using match in cases like this. Somehow it escaped me here ^_^

[bors]

⌛ Testing commit 90bc98c with merge fd0f292...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: petrochenkov
Pushing fd0f292 to master...