This text historically was copied verbatim from rust-lang/rust's own README [1]
with the intention of licensing projects the same as rustc's own license, namely
a dual MIT/Apache-2.0 license. The clause about "various BSD-like licenses"
isn't actually correct for almost all projects other than rust-lang/rust and
the wording around "both" was slightly ambiguous.
This commit updates the wording to match more precisely what's in the
standard library [2], namely clarifying that there aren't any BSD-like licenses
in this repository and that the source is licensable under either license, at
your own discretion.
[1]: f0fe716dbc (license)
[2]: f0fe716dbc/src/libstd/lib.rs (L5-L9)
The regular portion of the crate doesn't need anything from std
so turn off std for non-test. This allows this to be used from
projects which are also no_std.
