tracing: attempt to monomorphization is_enabled call

tracing/src/lib.rs

@@ -869,6 +869,13 @@ pub mod __macro_support {
     pub type Once = tracing_core::Once;
 }
 
+#[doc(hidden)]
+// resolves https://github.com/tokio-rs/tracing/issues/783 by forcing a monomorphization
+// in tracing, not downstream crates.
+pub fn is_enabled(meta: &crate::Metadata<'_>) -> bool {
+    crate::dispatcher::get_default(|current| current.enabled(meta))
+}
+
 mod sealed {
     pub trait Sealed {}
 }

tracing/src/macros.rs

@@ -1860,7 +1860,7 @@ macro_rules! is_enabled {
             true
         } else {
             let meta = $callsite.metadata();
-            $crate::dispatcher::get_default(|current| current.enabled(meta))
+            $crate::is_enabled(meta)
         }
     }};
 }