2 files changed, 52 insertions, 29 deletions

diff --git a/tests/ui/no_effect.rs b/tests/ui/no_effect.rs
index c52f4389192..7ffdeef6582 100644
--- a/tests/ui/no_effect.rs
+++ b/tests/ui/no_effect.rs
@@ -9,6 +9,22 @@
     clippy::useless_vec
 )]
 
+use std::fmt::Display;
+use std::ops::Shl;
+
+struct Cout;
+
+impl<T> Shl<T> for Cout
+where
+    T: Display,
+{
+    type Output = Self;
+    fn shl(self, rhs: T) -> Self::Output {
+        println!("{}", rhs);
+        self
+    }
+}
+
 struct Unit;
 struct Tuple(i32);
 struct Struct {
@@ -174,4 +190,11 @@ fn main() {
     GreetStruct1("world");
     GreetStruct2()("world");
     GreetStruct3 {}("world");
+
+    fn n() -> i32 {
+        42
+    }
+
+    Cout << 142;
+    Cout << n();
 }
diff --git a/tests/ui/no_effect.stderr b/tests/ui/no_effect.stderr
index feba35697f5..437e556a7a8 100644
--- a/tests/ui/no_effect.stderr
+++ b/tests/ui/no_effect.stderr
@@ -1,5 +1,5 @@
 error: statement with no effect
-  --> $DIR/no_effect.rs:98:5
+  --> $DIR/no_effect.rs:114:5
    |
 LL |     0;
    |     ^^
@@ -8,151 +8,151 @@ LL |     0;
    = help: to override `-D warnings` add `#[allow(clippy::no_effect)]`
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:101:5
+  --> $DIR/no_effect.rs:117:5
    |
 LL |     s2;
    |     ^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:103:5
+  --> $DIR/no_effect.rs:119:5
    |
 LL |     Unit;
    |     ^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:105:5
+  --> $DIR/no_effect.rs:121:5
    |
 LL |     Tuple(0);
    |     ^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:107:5
+  --> $DIR/no_effect.rs:123:5
    |
 LL |     Struct { field: 0 };
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:109:5
+  --> $DIR/no_effect.rs:125:5
    |
 LL |     Struct { ..s };
    |     ^^^^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:111:5
+  --> $DIR/no_effect.rs:127:5
    |
 LL |     Union { a: 0 };
    |     ^^^^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:113:5
+  --> $DIR/no_effect.rs:129:5
    |
 LL |     Enum::Tuple(0);
    |     ^^^^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:115:5
+  --> $DIR/no_effect.rs:131:5
    |
 LL |     Enum::Struct { field: 0 };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:117:5
+  --> $DIR/no_effect.rs:133:5
    |
 LL |     5 + 6;
    |     ^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:119:5
+  --> $DIR/no_effect.rs:135:5
    |
 LL |     *&42;
    |     ^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:121:5
+  --> $DIR/no_effect.rs:137:5
    |
 LL |     &6;
    |     ^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:123:5
+  --> $DIR/no_effect.rs:139:5
    |
 LL |     (5, 6, 7);
    |     ^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:125:5
+  --> $DIR/no_effect.rs:141:5
    |
 LL |     ..;
    |     ^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:127:5
+  --> $DIR/no_effect.rs:143:5
    |
 LL |     5..;
    |     ^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:129:5
+  --> $DIR/no_effect.rs:145:5
    |
 LL |     ..5;
    |     ^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:131:5
+  --> $DIR/no_effect.rs:147:5
    |
 LL |     5..6;
    |     ^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:133:5
+  --> $DIR/no_effect.rs:149:5
    |
 LL |     5..=6;
    |     ^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:135:5
+  --> $DIR/no_effect.rs:151:5
    |
 LL |     [42, 55];
    |     ^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:137:5
+  --> $DIR/no_effect.rs:153:5
    |
 LL |     [42, 55][1];
    |     ^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:139:5
+  --> $DIR/no_effect.rs:155:5
    |
 LL |     (42, 55).1;
    |     ^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:141:5
+  --> $DIR/no_effect.rs:157:5
    |
 LL |     [42; 55];
    |     ^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:143:5
+  --> $DIR/no_effect.rs:159:5
    |
 LL |     [42; 55][13];
    |     ^^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:146:5
+  --> $DIR/no_effect.rs:162:5
    |
 LL |     || x += 5;
    |     ^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:149:5
+  --> $DIR/no_effect.rs:165:5
    |
 LL |     FooString { s: s };
    |     ^^^^^^^^^^^^^^^^^^^
 
 error: binding to `_` prefixed variable with no side-effect
-  --> $DIR/no_effect.rs:151:5
+  --> $DIR/no_effect.rs:167:5
    |
 LL |     let _unused = 1;
    |     ^^^^^^^^^^^^^^^^
@@ -161,19 +161,19 @@ LL |     let _unused = 1;
    = help: to override `-D warnings` add `#[allow(clippy::no_effect_underscore_binding)]`
 
 error: binding to `_` prefixed variable with no side-effect
-  --> $DIR/no_effect.rs:154:5
+  --> $DIR/no_effect.rs:170:5
    |
 LL |     let _penguin = || println!("Some helpful closure");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: binding to `_` prefixed variable with no side-effect
-  --> $DIR/no_effect.rs:156:5
+  --> $DIR/no_effect.rs:172:5
    |
 LL |     let _duck = Struct { field: 0 };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: binding to `_` prefixed variable with no side-effect
-  --> $DIR/no_effect.rs:158:5
+  --> $DIR/no_effect.rs:174:5
    |
 LL |     let _cat = [2, 4, 6, 8][2];
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^