Extract Translator struct

compiler/rustc_error_messages/src/lib.rs

@@ -18,7 +18,7 @@ pub use fluent_bundle::{self, FluentArgs, FluentError, FluentValue};
 use fluent_syntax::parser::ParserError;
 use icu_provider_adapters::fallback::{LocaleFallbackProvider, LocaleFallbacker};
 use intl_memoizer::concurrent::IntlLangMemoizer;
-use rustc_data_structures::sync::IntoDynSyncSend;
+use rustc_data_structures::sync::{DynSend, IntoDynSyncSend};
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::Span;
 use smallvec::SmallVec;
@@ -204,16 +204,16 @@ fn register_functions(bundle: &mut FluentBundle) {
 
 /// Type alias for the result of `fallback_fluent_bundle` - a reference-counted pointer to a lazily
 /// evaluated fluent bundle.
-pub type LazyFallbackBundle = Arc<LazyLock<FluentBundle, impl FnOnce() -> FluentBundle>>;
+pub type LazyFallbackBundle =
+    Arc<LazyLock<FluentBundle, Box<dyn FnOnce() -> FluentBundle + DynSend>>>;
 
 /// Return the default `FluentBundle` with standard "en-US" diagnostic messages.
 #[instrument(level = "trace", skip(resources))]
-#[define_opaque(LazyFallbackBundle)]
 pub fn fallback_fluent_bundle(
     resources: Vec<&'static str>,
     with_directionality_markers: bool,
 ) -> LazyFallbackBundle {
-    Arc::new(LazyLock::new(move || {
+    Arc::new(LazyLock::new(Box::new(move || {
         let mut fallback_bundle = new_bundle(vec![langid!("en-US")]);
 
         register_functions(&mut fallback_bundle);
@@ -228,7 +228,7 @@ pub fn fallback_fluent_bundle(
         }
 
         fallback_bundle
-    }))
+    })))
 }
 
 /// Identifier for the Fluent message/attribute corresponding to a diagnostic message.