Support no_std

[glandium]

Fixes #3.

[dtolnay]

Cargo features are required to be additive, i.e. any code that compiles without the feature must also compile with the feature. Could you come up with a different way to implement this?

[glandium]

It's rather unconventional to support both std::fmt::Write and std::io::Write at the same time. How would you go about it?

[glandium]

Oh, I see issue #5.

[dtolnay]

Thanks, this looks promising.

[dtolnay]

Check out C-FEATURE for recommendations on how to name Cargo features.

[glandium]

FWIW, I mimicked the libc crate here.

[dtolnay]

Yeah sadly libc got this wrong, rust-lang/libc#657. It will be fixed in their next release.

[dtolnay]

I think this is still problematic.

Cargo features are required to be additive, i.e. any code that compiles without the feature must also compile with the feature.

In this case if someone downstream writes a type:

struct u24(/* ... */);

impl Integer for u24 {
    fn fmt<W: fmt::Write>(self, W) -> fmt::Result {
        /* ... */
    }
}

their code would compile fine when our std feature is not enabled but would break when some unrelated crate depends on our std feature. That makes the feature not additive.

See C-SEALED for a pattern that would work here.

[dtolnay]

Thanks!

[dtolnay]

I released 0.4.0 with this change.