Move common code to `WhereClause`

1 files changed, 7 insertions, 0 deletions

diff --git a/src/librustc_hir/hir.rs b/src/librustc_hir/hir.rs
index ef398ab25d3..a46871ac807 100644
--- a/src/librustc_hir/hir.rs
+++ b/src/librustc_hir/hir.rs
@@ -525,6 +525,13 @@ impl WhereClause<'_> {
     pub fn span_for_predicates_or_empty_place(&self) -> Span {
         self.span
     }
+
+    /// `Span` where further predicates would be suggested, accounting for trailing commas, like
+    ///  in `fn foo<T>(t: T) where T: Foo,` so we don't suggest two trailing commas.
+    pub fn tail_span_for_suggestion(&self) -> Span {
+        let end = self.span_for_predicates_or_empty_place().shrink_to_hi();
+        self.predicates.last().map(|p| p.span()).unwrap_or(end).shrink_to_hi().to(end)
+    }
 }
 
 /// A single predicate in a where-clause.