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-rw-r--r--compiler/rustc_middle/src/query/mod.rs14
1 files changed, 14 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 46a960d9945..1302027aabb 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -748,6 +748,15 @@ rustc_queries! {
         }
     }
 
+    /// Compute the conditions that need to hold for a conditionally-const item to be const.
+    /// That is, compute the set of `~const` where clauses for a given item.
+    ///
+    /// This can be thought of as the `~const` equivalent of `predicates_of`. These are the
+    /// predicates that need to be proven at usage sites, and can be assumed at definition.
+    ///
+    /// This query also computes the `~const` where clauses for associated types, which are
+    /// not "const", but which have item bounds which may be `~const`. These must hold for
+    /// the `~const` item bound to hold.
     query const_conditions(
         key: DefId
     ) -> ty::ConstConditions<'tcx> {
@@ -757,6 +766,11 @@ rustc_queries! {
         separate_provide_extern
     }
 
+    /// Compute the const bounds that are implied for a conditionally-const item.
+    ///
+    /// This can be though of as the `~const` equivalent of `explicit_item_bounds`. These
+    /// are the predicates that need to proven at definition sites, and can be assumed at
+    /// usage sites.
     query explicit_implied_const_bounds(
         key: DefId
     ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::PolyTraitRef<'tcx>, Span)]> {