Rework `ast::BinOpKind::to_string` and `ast::UnOp::to_string`.

- Rename them both `as_str`, which is the typical name for a function
  that returns a `&str`. (`to_string` is appropriate for functions
  returning `String` or maybe `Cow<'a, str>`.)
- Change `UnOp::as_str` from an associated function (weird!) to a
  method.
- Avoid needless `self` dereferences.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/expr.rs b/src/expr.rs
index fa941e6146a..60e0e007b1d 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -1933,7 +1933,7 @@ fn rewrite_unary_op(
     shape: Shape,
 ) -> Option<String> {
     // For some reason, an UnOp is not spanned like BinOp!
-    rewrite_unary_prefix(context, ast::UnOp::to_string(op), expr, shape)
+    rewrite_unary_prefix(context, op.as_str(), expr, shape)
 }
 
 pub(crate) enum RhsAssignKind<'ast> {