Suggest .copied() for map_clone on iterators too

rust-lang · Apr 28, 2019 · 770de14 · 770de14
1 parent 09a0422
commit 770de14
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Showing 3 changed files with 10 additions and 13 deletions.
diff --git a/clippy_lints/src/map_clone.rs b/clippy_lints/src/map_clone.rs
@@ -52,8 +52,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MapClone {
  if args.len() == 2;
  if method.ident.as_str() == "map";
  let ty = cx.tables.expr_ty(&args[0]);
- let is_option = match_type(cx, ty, &paths::OPTION);
- if is_option || match_trait_method(cx, e, &paths::ITERATOR);
+ if match_type(cx, ty, &paths::OPTION) || match_trait_method(cx, e, &paths::ITERATOR);
  if let hir::ExprKind::Closure(_, _, body_id, _, _) = args[1].node;
  let closure_body = cx.tcx.hir().body(body_id);
  let closure_expr = remove_blocks(&closure_body.value);
@@ -63,16 +62,14 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MapClone {
  hir::BindingAnnotation::Unannotated, .., name, None
  ) = inner.node {
  if ident_eq(name, closure_expr) {
- // FIXME When Iterator::copied() stabilizes we can remove is_option
- // from here and the other lint() calls
- lint(cx, e.span, args[0].span, is_option);
+ lint(cx, e.span, args[0].span, true);
  }
  },
  hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, .., name, None) => {
  match closure_expr.node {
  hir::ExprKind::Unary(hir::UnOp::UnDeref, ref inner) => {
  if ident_eq(name, inner) && !cx.tables.expr_ty(inner).is_box() {
- lint(cx, e.span, args[0].span, is_option);
+ lint(cx, e.span, args[0].span, true);
  }
  },
  hir::ExprKind::MethodCall(ref method, _, ref obj) => {
@@ -82,7 +79,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MapClone {
  let obj_ty = cx.tables.expr_ty(&obj[0]);
  if let ty::Ref(_, ty, _) = obj_ty.sty {
  let copy = is_copy(cx, ty);
- lint(cx, e.span, args[0].span, is_option && copy);
+ lint(cx, e.span, args[0].span, copy);
  } else {
  lint_needless_cloning(cx, e.span, args[0].span);
  }

diff --git a/tests/ui/map_clone.fixed b/tests/ui/map_clone.fixed
@@ -6,9 +6,9 @@
 #![allow(clippy::redundant_closure)]
 
 fn main() {
- let _: Vec<i8> = vec![5_i8; 6].iter().cloned().collect();
+ let _: Vec<i8> = vec![5_i8; 6].iter().copied().collect();
  let _: Vec<String> = vec![String::new()].iter().cloned().collect();
- let _: Vec<u32> = vec![42, 43].iter().cloned().collect();
+ let _: Vec<u32> = vec![42, 43].iter().copied().collect();
  let _: Option<u64> = Some(Box::new(16)).map(|b| *b);
  let _: Option<u64> = Some(&16).copied();
  let _: Option<u8> = Some(&1).copied();

diff --git a/tests/ui/map_clone.stderr b/tests/ui/map_clone.stderr
@@ -1,8 +1,8 @@
-error: You are using an explicit closure for cloning elements
+error: You are using an explicit closure for copying elements
  --> $DIR/map_clone.rs:9:22
  |
 LL | let _: Vec<i8> = vec![5_i8; 6].iter().map(|x| *x).collect();
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![5_i8; 6].iter().cloned()`
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `copied` method: `vec![5_i8; 6].iter().copied()`
  |
  = note: `-D clippy::map-clone` implied by `-D warnings`
 
@@ -12,11 +12,11 @@ error: You are using an explicit closure for cloning elements
 LL | let _: Vec<String> = vec![String::new()].iter().map(|x| x.clone()).collect();
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![String::new()].iter().cloned()`
 
-error: You are using an explicit closure for cloning elements
+error: You are using an explicit closure for copying elements
  --> $DIR/map_clone.rs:11:23
  |
 LL | let _: Vec<u32> = vec![42, 43].iter().map(|&x| x).collect();
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![42, 43].iter().cloned()`
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `copied` method: `vec![42, 43].iter().copied()`
 
 error: You are using an explicit closure for copying elements
  --> $DIR/map_clone.rs:13:26