or_fun_call warns on enum variant construction.

[Stebalien]

I have the following line in my project:

self.write_to_fmt(&mut Adapter(f)).or(Err(fmt::Error))

Err(fmt::Error) is a constant but clippy complains that I'm calling a function.

[mcarton]

Err (as all parametered enum variants) is also a function. But Clippy should not warn there indeed.

[llogiq]

I've seen other instances where functions that were basically constructors (and fully inclined) were suggested to use lazily. Alas, we don't have a measurement for 'this is expensive' in clippy. Perhaps the message should reflect this.

[Stebalien]

Thanks!

[llogiq]

Thank you for letting us know!