Add a compile_error!() when central crate features clash
#110
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this prevents users from accidentally using both features, as they are mutually exclusive. it also includes a fix to calm`rust-analyzer`, as it has an option to check all features at the same time. i have that feature enabled in my editor by default, which caused around 100 errors and prevented "true" lints from showing in my IDE
in case the dependencies ever change, it's preferable to have user-facing features in here this also defaults to using the `v4l2` module branch when both features are enabled, allowing for easier development when all features are being checked by the IDE.
this also has some minor formatting changes to abide by the CommonMark standard
| #[cfg(all(feature = "v4l2", feature = "libv4l"))] | ||
| pub use v4l_sys; |
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Why not do what you've done in the second patch (but the other way around):
- Remove these two lines;
- Change the above to:
-#[cfg(all(feature = "libv4l", not(feature = "v4l2")))] +#[cfg(feature = "v4l2")] pub use v4l2_sys as v4l_sys;
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I would also prefer this, but I found that doing so breaks one of the features.
On the other hand, it doesn't occur in api.rs since we're not already re-exporting one of its modules. If you find a way to do it, though, please let me know!
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It would match the choice in api.rs to prefer v4l2 code in the case that both features are contemporarily enabled, but it is less of an issue now that the comment has been removed.
Either way, this seems better to me:
diff --git a/src/lib.rs b/src/lib.rs
index 2272aeb..1237262 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -74,16 +74,12 @@ compile_error!(
add `default-features = false` as a dependency key."
);
-#[cfg(all(feature = "libv4l", not(feature = "v4l2")))]
-pub use v4l_sys;
-
-#[cfg(all(feature = "v4l2", not(feature = "libv4l")))]
-pub use v4l2_sys as v4l_sys;
-
-// calms down rust-analyzer when `rust-analyzer.cargo.features = "all"`,
-// though the `compile_error!()` above prevents this from being a valid,
+// calm down rust-analyzer when `rust-analyzer.cargo.features = "all"` by having only one `v4l_sys`
+// crate in scope, even though the `compile_error!()` above prevents this from being a valid,
// compilable configuration.
-#[cfg(all(feature = "v4l2", feature = "libv4l"))]
+#[cfg(feature = "v4l2")]
+pub use v4l2_sys as v4l_sys;
+#[cfg(all(feature = "libv4l", not(feature = "v4l2")))]
pub use v4l_sys;
pub mod v4l2;
| #[cfg(feature = "v4l-sys")] | ||
| #[cfg(all(feature = "libv4l", feature = "v4l2"))] | ||
| compile_error!( | ||
| "You may not enable both `v4l-sys` and `v4l2-sys` features at the same time.\ |
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You name these features but they're implicit from the optional dependencies, and "renamed" (but without "dep:...") to v4l2 and libv4l. I think we should specify exactly what the user is enabling, or expected ot enable:
| "You may not enable both `v4l-sys` and `v4l2-sys` features at the same time.\ | |
| "You may not enable both `libv4l` and `v4l2` features at the same time.\ |
| #[cfg(all(feature = "v4l2", feature = "libv4l"))] | ||
| pub use v4l_sys; |
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It would match the choice in api.rs to prefer v4l2 code in the case that both features are contemporarily enabled, but it is less of an issue now that the comment has been removed.
Either way, this seems better to me:
diff --git a/src/lib.rs b/src/lib.rs
index 2272aeb..1237262 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -74,16 +74,12 @@ compile_error!(
add `default-features = false` as a dependency key."
);
-#[cfg(all(feature = "libv4l", not(feature = "v4l2")))]
-pub use v4l_sys;
-
-#[cfg(all(feature = "v4l2", not(feature = "libv4l")))]
-pub use v4l2_sys as v4l_sys;
-
-// calms down rust-analyzer when `rust-analyzer.cargo.features = "all"`,
-// though the `compile_error!()` above prevents this from being a valid,
+// calm down rust-analyzer when `rust-analyzer.cargo.features = "all"` by having only one `v4l_sys`
+// crate in scope, even though the `compile_error!()` above prevents this from being a valid,
// compilable configuration.
-#[cfg(all(feature = "v4l2", feature = "libv4l"))]
+#[cfg(feature = "v4l2")]
+pub use v4l2_sys as v4l_sys;
+#[cfg(all(feature = "libv4l", not(feature = "v4l2")))]
pub use v4l_sys;
pub mod v4l2;
Fixes #94, fixes #108
This prevents users from accidentally using both features, as they are mutually exclusive.
Please let me know if you would like any changes! ✨