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| author | Oliver S̶c̶h̶n̶e̶i̶d̶e̶r Scherer <github35764891676564198441@oli-obk.de> | 2018-10-10 22:35:02 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-10-10 22:35:02 +0200 |
| commit | dd11ffac0b944eddc605a06a742b02f43c57755f (patch) | |
| tree | 0c15a7cd8ac537bf33eb4d45ba91e2bd7803ad82 | |
| parent | f6882ede4dc32684e000d256644c9e192ea8c738 (diff) | |
| parent | f9e4f5695dca025a868e3cdc24bea387c7c475f9 (diff) | |
| download | rust-dd11ffac0b944eddc605a06a742b02f43c57755f.tar.gz rust-dd11ffac0b944eddc605a06a742b02f43c57755f.zip | |
Merge pull request #3292 from kimsnj/commutative_assign_op
Limit commutative assign op lint to primitive types
| -rw-r--r-- | clippy_lints/src/assign_ops.rs | 4 | ||||
| -rw-r--r-- | tests/ui/assign_ops2.rs | 15 | ||||
| -rw-r--r-- | tests/ui/assign_ops2.stderr | 10 |
3 files changed, 27 insertions, 2 deletions
diff --git a/clippy_lints/src/assign_ops.rs b/clippy_lints/src/assign_ops.rs index 3fbac7bc153..803c79d42fc 100644 --- a/clippy_lints/src/assign_ops.rs +++ b/clippy_lints/src/assign_ops.rs @@ -215,7 +215,9 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssignOps { lint(assignee, r); } // a = b commutative_op a - if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, r) { + // Limited to primitive type as these ops are know to be commutative + if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, r) + && cx.tables.expr_ty(assignee).is_primitive_ty() { match op.node { hir::BinOpKind::Add | hir::BinOpKind::Mul diff --git a/tests/ui/assign_ops2.rs b/tests/ui/assign_ops2.rs index 9eef898c9a7..60a9d2fb73e 100644 --- a/tests/ui/assign_ops2.rs +++ b/tests/ui/assign_ops2.rs @@ -53,3 +53,18 @@ impl MulAssign<i64> for Wrap { *self = *self * rhs } } + +fn cow_add_assign() { + use std::borrow::Cow; + let mut buf = Cow::Owned(String::from("bar")); + let cows = Cow::Borrowed("foo"); + + // this can be linted + buf = buf + cows.clone(); + + // this should not as cow<str> Add is not commutative + buf = cows + buf; + println!("{}", buf); + +} + diff --git a/tests/ui/assign_ops2.stderr b/tests/ui/assign_ops2.stderr index 8e44fc13bb7..bd49c3cdd80 100644 --- a/tests/ui/assign_ops2.stderr +++ b/tests/ui/assign_ops2.stderr @@ -126,5 +126,13 @@ help: or 26 | a = a * a * a; | ^^^^^^^^^^^^^ -error: aborting due to 9 previous errors +error: manual implementation of an assign operation + --> $DIR/assign_ops2.rs:63:5 + | +63 | buf = buf + cows.clone(); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `buf += cows.clone()` + | + = note: `-D clippy::assign-op-pattern` implied by `-D warnings` + +error: aborting due to 10 previous errors |