Are floats really dependency free?

[xaviershay]

As mentioned in http://blog.phil-opp.com/rust-os/setup-rust.html

The core library is added implicitly when using #![no_std] and provides basic standard library features like Option or Iterator. According to the documentation it is “dependency-free”. But it actually has some dependencies, for example on fmod and fmodf.

This strikes me as a bug, either in the core library or in the documentation.

Previously reported at https://github.com/phil-opp/phil-opp.github.io/issues/7, moving here.

[huonw]

This is a dupe of #27200 (and somewhat related to #27701 and #26449).

Thanks for filing!

[alexcrichton]

In general, however, I don't necessarily consider fmod and fmodf as dependencies of libcore that need to be worried about. Linking with --gc-sections will eliminate them and otherwise you still have to deal with basic dependencies like memcpy and memmove, so having a few small "very well known" functions being unimplemented I think is fine (although they should obviously be minimized where possible).

If we could I'd love to only provide Div/Rem on floats in the standard library, but coherence forces our hand of putting them in libcore, and it's not necessarily the end of the world.

[steveklabnik]

I'm still not sure that we should describe libcore as 'dependency free' if there are dependencies, though. Shouldn't that be a doc issue?