1 files changed, 51 insertions, 0 deletions
diff --git a/compiler/rustc_ty_utils/src/common_traits.rs b/compiler/rustc_ty_utils/src/common_traits.rs
new file mode 100644
index 000000000..cedc84d97
--- /dev/null
+++ b/compiler/rustc_ty_utils/src/common_traits.rs
@@ -0,0 +1,51 @@
+//! Queries for checking whether a type implements one of a few common traits.
+
+use rustc_hir::lang_items::LangItem;
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_span::DUMMY_SP;
+use rustc_trait_selection::traits;
+
+fn is_copy_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+    is_item_raw(tcx, query, LangItem::Copy)
+}
+
+fn is_sized_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+    is_item_raw(tcx, query, LangItem::Sized)
+}
+
+fn is_freeze_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+    is_item_raw(tcx, query, LangItem::Freeze)
+}
+
+fn is_unpin_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+    is_item_raw(tcx, query, LangItem::Unpin)
+}
+
+fn is_item_raw<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>,
+    item: LangItem,
+) -> bool {
+    let (param_env, ty) = query.into_parts();
+    let trait_def_id = tcx.require_lang_item(item, None);
+    tcx.infer_ctxt().enter(|infcx| {
+        traits::type_known_to_meet_bound_modulo_regions(
+            &infcx,
+            param_env,
+            ty,
+            trait_def_id,
+            DUMMY_SP,
+        )
+    })
+}
+
+pub(crate) fn provide(providers: &mut ty::query::Providers) {
+    *providers = ty::query::Providers {
+        is_copy_raw,
+        is_sized_raw,
+        is_freeze_raw,
+        is_unpin_raw,
+        ..*providers
+    };
+}