In no_std context, use no_std num-traits.

[cbiffle]

This crate was not actually no_std compatible because it (1) used
num-traits with the std feature, and (2) relied on the Float trait,
which is unavailable in no_std.

I have altered it to rely on FloatCore instead and passed the feature
flag through to the dependency.

Had to bump the version of num-traits required, because FloatCore only
appeared in 0.2.1.

[cbiffle]

Incidentally, it looks like you're trying to test the no_std build on Travis. Excellent!

However, Cargo does not transitively enforce no_std-ness. Simply clearing the std feature at the root package is not enough.

The safest way to avoid this is to build for a target triple with the OS component of none. Such targets don't ship with libstd and so the build will fail if you transitively depend on it. (This is how I noticed the issue.)

I've checked this target, which might be an option:

cargo build --target thumbv7em-none-eabihf --no-default-features

You won't be able to run (or build) your tests on such a target, as the test framework doesn't support no_std. (You're currently able to test no_std only because of the no-enforcement issue I mentioned above.)

[mbrubeck]

Thanks!