From 28f735bb26706af3dddc7fa52ea4122a408cb023 Mon Sep 17 00:00:00 2001
From: Bruno Kirschner <bruno.kirschner@online.de>
Date: Sun, 3 Jun 2018 18:46:11 +0200
Subject: [PATCH] Cleaned implements_ord helper function in boolean lint file.

---
 clippy_lints/src/booleans.rs | 24 +++++++++---------------
 tests/ui/booleans.rs         | 10 ++++++++++
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/clippy_lints/src/booleans.rs b/clippy_lints/src/booleans.rs
index 8816d50c5c26..0a453618e193 100644
--- a/clippy_lints/src/booleans.rs
+++ b/clippy_lints/src/booleans.rs
@@ -123,10 +123,9 @@ fn run(&mut self, e: &'v Expr) -> Result<Bool, String> {
             let negated = match e.node {
                 ExprBinary(binop, ref lhs, ref rhs) => {
  
-                    match implements_ord(self.cx, lhs) {
-                        Some(true) => (),
-                        _ => continue,
-                    };
+                    if !implements_ord(self.cx, lhs) {
+                        continue;
+                    }
 
                     let mk_expr = |op| {
                         Expr {
@@ -181,10 +180,9 @@ fn simplify_not(&self, expr: &Expr) -> Option<String> {
         match expr.node {
             ExprBinary(binop, ref lhs, ref rhs) => {
 
-                match implements_ord(self.cx, lhs) {
-                    Some(true) => (),
-                    _ => return None,
-                };
+                if !implements_ord(self.cx, lhs) {
+                    return None;
+                }
 
                 match binop.node {
                     BiEq => Some(" != "),
@@ -458,12 +456,8 @@ fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
 }
 
 
-fn implements_ord<'a, 'tcx>(cx: &'a LateContext<'a, 'tcx>, expr: &Expr) -> Option<bool> {
+fn implements_ord<'a, 'tcx>(cx: &'a LateContext<'a, 'tcx>, expr: &Expr) -> bool {
     let ty = cx.tables.expr_ty(expr);
-
-    return if let Some(id) = get_trait_def_id(cx, &paths::ORD) {
-        Some(implements_trait(cx, ty, id, &[]))
-    } else {
-        None
-    };
+    get_trait_def_id(cx, &paths::ORD)
+        .map_or(false, |id| implements_trait(cx, ty, id, &[]))
 }
diff --git a/tests/ui/booleans.rs b/tests/ui/booleans.rs
index 78e876e51822..9daf15d378cc 100644
--- a/tests/ui/booleans.rs
+++ b/tests/ui/booleans.rs
@@ -114,3 +114,13 @@ fn warn_for_built_in_methods_with_negation() {
     if !res.is_some() { }
     if !res.is_none() { }
 }
+
+#[allow(neg_cmp_op_on_partial_ord)]
+fn dont_warn_for_negated_partial_ord_comparision() {
+    let a: f64 = unimplemented!();
+    let b: f64 = unimplemented!();
+    let _ = !(a < b);
+    let _ = !(a <= b);
+    let _ = !(a > b);
+    let _ = !(a >= b);
+}