Re-export derives from serde

serde-rs · Mar 21, 2017 · 13886435a600bd049e4e9db6e22fac6a0113784a · 1388643
1 parent 08e2182
commit 13886435a600bd049e4e9db6e22fac6a0113784a
Unified Split

Showing with 48 additions and 0 deletions.

+1 −0 serde/Cargo.toml

+47 −0 serde/src/lib.rs
diff --git a/serde/Cargo.toml b/serde/Cargo.toml
@@ -17,6 +17,7 @@ travis-ci = { repository = "serde-rs/serde" }
 [features]
 default = ["std"]
+  
+derive = ["serde_derive"]
 std = []
 unstable = []

diff --git a/serde/src/lib.rs b/serde/src/lib.rs
@@ -106,3 +106,50 @@ mod utils;
 // Generated code uses these to support no_std. Not public API.
 #[doc(hidden)]
 pub mod export;
+  
+
+  
+// Re-export #[derive(Serialize, Deserialize)].
+  
+//
+  
+// This is a workaround for https://github.com/rust-lang/cargo/issues/1286.
+  
+// Without this re-export, crates that put Serde derives behind a cfg_attr would
+  
+// need to use some silly feature name that depends on both serde and
+  
+// serde_derive.
+  
+//
+  
+//     [features]
+  
+//     serde-impls = ["serde", "serde_derive"]
+  
+//
+  
+//     [dependencies]
+  
+//     serde = { version = "1.0", optional = true }
+  
+//     serde_derive = { version = "1.0", optional = true }
+  
+//
+  
+//     # Used like this:
+  
+//     # #[cfg(feature = "serde-impls")]
+  
+//     # #[macro_use]
+  
+//     # extern crate serde_derive;
+  
+//     #
+  
+//     # #[cfg_attr(feature = "serde-impls", derive(Serialize, Deserialize))]
+  
+//     # struct S { /* ... */ }
+  
+//
+  
+// The re-exported derives allow crates to use "serde" as the name of their
+  
+// Serde feature which is more intuitive.
+  
+//
+  
+//     [dependencies]
+  
+//     serde = { version = "1.0", optional = true, features = ["derive"] }
+  
+//
+  
+//     # Used like this:
+  
+//     # #[cfg(feature = "serde")]
+  
+//     # #[macro_use]
+  
+//     # extern crate serde;
+  
+//     #
+  
+//     # #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+  
+//     # struct S { /* ... */ }
+  
+//
+  
+// The reason re-exporting is not enabled by default is that disabling it would
+  
+// be annoying for crates that provide handwritten impls or data formats. They
+  
+// would need to disable default features and then explicitly re-enable std.
+  
+#[cfg(feature = "serde_derive")]
+  
+#[allow(unused_imports)]
+  
+#[macro_use]
+  
+extern crate serde_derive;
+  
+#[cfg(feature = "serde_derive")]
+  
+#[doc(hidden)]
+  
+pub use serde_derive::*;