fix cfg feature macro

Author: k-nasa

tracing-subscriber/src/lib.rs

@@ -116,20 +116,20 @@ pub use filter::EnvFilter;
 
 pub use layer::Layer;
 
-cfg_fmt! {
+cfg_feature!("fmt", {
     pub mod fmt;
-    pub use fmt::Subscriber as FmtSubscriber;
     pub use fmt::fmt;
-}
+    pub use fmt::Subscriber as FmtSubscriber;
+});
 
-cfg_registry! {
+cfg_feature!("registry", {
     pub use registry::Registry;
 
     ///
     pub fn registry() -> Registry {
         Registry::default()
     }
-}
+});
 
 use std::default::Default;
 /// Tracks the currently executing span on a per-thread basis.

tracing-subscriber/src/macros.rs

@@ -13,25 +13,11 @@ macro_rules! try_lock {
     };
 }
 
-/// Declares fmt items.
-#[doc(hidden)]
-macro_rules! cfg_fmt {
-    ($($item:item)*) => {
+macro_rules! cfg_feature {
+    ($name:expr, { $($item:item)* }) => {
         $(
-            #[cfg(feature = "fmt")]
-            #[cfg_attr(docsrs, doc(cfg(feature = "fmt")))]
-            $item
-        )*
-    }
-}
-
-/// Declares registry items.
-#[doc(hidden)]
-macro_rules! cfg_registry {
-    ($($item:item)*) => {
-        $(
-            #[cfg(feature = "registry")]
-            #[cfg_attr(docsrs, doc(cfg(feature = "registry")))]
+            #[cfg(feature = $name)]
+            #[cfg_attr(docsrs, doc(cfg(feature = $name)))]
             $item
         )*
     }