Remove `identity_future` indirection

This was previously needed because the indirection used to hide some unexplained lifetime errors, which it turned out were related to the `min_choice` algorithm.

Removing the indirection also solves a couple of cycle errors, large moves and makes async blocks support the `#[track_caller]` annotation.

1 files changed, 1 insertions, 8 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 66d74fd05a6..b6e70bd9e33 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -3025,8 +3025,6 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     }
                 };
 
-                let identity_future = tcx.require_lang_item(LangItem::IdentityFuture, None);
-
                 // Don't print the tuple of capture types
                 'print: {
                     if !is_upvar_tys_infer_tuple {
@@ -3039,12 +3037,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                                 None => err.note(&msg),
                             },
                             ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) => {
-                                // Avoid printing the future from `core::future::identity_future`, it's not helpful
-                                if tcx.parent(*def_id) == identity_future {
-                                    break 'print;
-                                }
-
-                                // If the previous type is `identity_future`, this is the future generated by the body of an async function.
+                                // If the previous type is async fn, this is the future generated by the body of an async function.
                                 // Avoid printing it twice (it was already printed in the `ty::Generator` arm below).
                                 let is_future = tcx.ty_is_opaque_future(ty);
                                 debug!(