Cargo Features

rls-span has no features set by default.

[dependencies]
rls-span = { version = "0.5.4", features = ["nightly", "serialize-rustc", "derive"] }
nightly
serialize-rustc = rustc-serialize
derive

Enables derive of serde

serde:

Provide derive(Serialize, Deserialize) macros.

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

rustc-serialize serialize-rustc?