rust cargo : how to use different features for a dep when a particular feature is enabled?

Question

例如，我定义了 2 个没有依赖关系的特性:

[features]
default = []
py2 = []
py3 = []

基于选定的功能 (--features py3) 我想为依赖项 (cpython) 启用不同的功能:

[dependencies.cpython]
default-features = false
# features = ["python27-sys"]      I want to select this if py2 is enabled
features = ["python3-sys"]
optional = true

我可以这样做吗？或者我也可以从命令行为依赖项选择功能吗？

Answer 1

讨论了here .可以使用 / 来完成。

[features]
default = []
py2 = ["cpython", "cpython/python27-sys"]
py3 = ["cpython", "cpython/python3-sys"]
unstable = []

[dependencies.cpython]
# git = "https://github.com/dgrunwald/rust-cpython.git"
default-features = false
optional = true

我在文档或官方页面上什么也没看到。