I want to conditionally compile my source code using cfg
with Cargo,
after Googling for a while,
it seems that the solution is to use cargo --features
.
http://doc.crates.io/manifest.html
I tried adding a few
#[cfg(feature = "foo")]
in the source code and
cargo build --features foo
, but it says
Package `xxx v0.0.1 (file:///C:/yyy/xxx)` does not have these features: `foo`
How can I let cargo identify the features? Do I have to add something in Cargo.toml
?
Here's the version of rustc
and cargo
I am using:
C:\>rustc --version
rustc 0.13.0-nightly (42deaa5e4 2014-12-16 17:51:23 +0000)
C:\>cargo --version
cargo 0.0.1-pre-nightly (5af754d 2014-12-18 01:50:48 +0000)
You have to introduce the existing features in your Cargo.toml
.
I was able to conditionally compile by doing the following:
In Cargo.toml
, create a features
section and introduce a certain feature name:
[features]
customfeature = [] # feature has no explicit dependencies
If you want your feature to have specific dependencies check the examples in the documentation.
In your code, use #[cfg(feature="customfeature")]
Run cargo build --features customfeature
Since your steps 2 & 3 seem to be fine, there must probably be a problem with your Cargo.toml
.