merge explicit_into_iter_fn_arg into useless_conversion

tests/ui/explicit_into_iter_fn_arg.fixed

@@ -1,33 +0,0 @@
-//@run-rustfix
-
-#![allow(unused, clippy::useless_conversion)]
-#![warn(clippy::explicit_into_iter_fn_arg)]
-
-fn a<T>(_: T) {}
-fn b<T: IntoIterator<Item = i32>>(_: T) {}
-fn c(_: impl IntoIterator<Item = i32>) {}
-fn d<T>(_: T)
-where
-    T: IntoIterator<Item = i32>,
-{
-}
-fn f(_: std::vec::IntoIter<i32>) {}
-
-fn main() {
-    a(vec![1, 2].into_iter());
-    b(vec![1, 2]);
-    c(vec![1, 2]);
-    d(vec![1, 2]);
-    b([&1, &2, &3].into_iter().cloned());
-
-    // Don't lint chained `.into_iter().into_iter()` calls. Covered by useless_conversion.
-    b(vec![1, 2].into_iter().into_iter());
-    b(vec![1, 2].into_iter().into_iter().into_iter());
-
-    macro_rules! macro_generated {
-        () => {
-            vec![1, 2].into_iter()
-        };
-    }
-    b(macro_generated!());
-}

tests/ui/explicit_into_iter_fn_arg.rs

@@ -1,33 +0,0 @@
-//@run-rustfix
-
-#![allow(unused, clippy::useless_conversion)]
-#![warn(clippy::explicit_into_iter_fn_arg)]
-
-fn a<T>(_: T) {}
-fn b<T: IntoIterator<Item = i32>>(_: T) {}
-fn c(_: impl IntoIterator<Item = i32>) {}
-fn d<T>(_: T)
-where
-    T: IntoIterator<Item = i32>,
-{
-}
-fn f(_: std::vec::IntoIter<i32>) {}
-
-fn main() {
-    a(vec![1, 2].into_iter());
-    b(vec![1, 2].into_iter());
-    c(vec![1, 2].into_iter());
-    d(vec![1, 2].into_iter());
-    b([&1, &2, &3].into_iter().cloned());
-
-    // Don't lint chained `.into_iter().into_iter()` calls. Covered by useless_conversion.
-    b(vec![1, 2].into_iter().into_iter());
-    b(vec![1, 2].into_iter().into_iter().into_iter());
-
-    macro_rules! macro_generated {
-        () => {
-            vec![1, 2].into_iter()
-        };
-    }
-    b(macro_generated!());
-}

tests/ui/explicit_into_iter_fn_arg.stderr

@@ -1,39 +0,0 @@
-error: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
-  --> $DIR/explicit_into_iter_fn_arg.rs:18:7
-   |
-LL |     b(vec![1, 2].into_iter());
-   |       ^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2]`
-   |
-note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
-  --> $DIR/explicit_into_iter_fn_arg.rs:7:9
-   |
-LL | fn b<T: IntoIterator<Item = i32>>(_: T) {}
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: `-D clippy::explicit-into-iter-fn-arg` implied by `-D warnings`
-
-error: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
-  --> $DIR/explicit_into_iter_fn_arg.rs:19:7
-   |
-LL |     c(vec![1, 2].into_iter());
-   |       ^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2]`
-   |
-note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
-  --> $DIR/explicit_into_iter_fn_arg.rs:8:14
-   |
-LL | fn c(_: impl IntoIterator<Item = i32>) {}
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
-  --> $DIR/explicit_into_iter_fn_arg.rs:20:7
-   |
-LL |     d(vec![1, 2].into_iter());
-   |       ^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2]`
-   |
-note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
-  --> $DIR/explicit_into_iter_fn_arg.rs:11:8
-   |
-LL |     T: IntoIterator<Item = i32>,
-   |        ^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to 3 previous errors
-

tests/ui/useless_conversion.fixed

@@ -155,6 +155,35 @@ fn main() {
     let _ = vec![s4, s4, s4].into_iter();
 }
 
+#[allow(dead_code)]
+fn explicit_into_iter_fn_arg() {
+    fn a<T>(_: T) {}
+    fn b<T: IntoIterator<Item = i32>>(_: T) {}
+    fn c(_: impl IntoIterator<Item = i32>) {}
+    fn d<T>(_: T)
+    where
+        T: IntoIterator<Item = i32>,
+    {
+    }
+    fn f(_: std::vec::IntoIter<i32>) {}
+
+    a(vec![1, 2].into_iter());
+    b(vec![1, 2]);
+    c(vec![1, 2]);
+    d(vec![1, 2]);
+    b([&1, &2, &3].into_iter().cloned());
+
+    b(vec![1, 2]);
+    b(vec![1, 2]);
+
+    macro_rules! macro_generated {
+        () => {
+            vec![1, 2].into_iter()
+        };
+    }
+    b(macro_generated!());
+}
+
 #[derive(Copy, Clone)]
 struct Foo<const C: char>;
 

tests/ui/useless_conversion.rs

@@ -155,6 +155,35 @@ fn main() {
     let _ = vec![s4, s4, s4].into_iter().into_iter();
 }
 
+#[allow(dead_code)]
+fn explicit_into_iter_fn_arg() {
+    fn a<T>(_: T) {}
+    fn b<T: IntoIterator<Item = i32>>(_: T) {}
+    fn c(_: impl IntoIterator<Item = i32>) {}
+    fn d<T>(_: T)
+    where
+        T: IntoIterator<Item = i32>,
+    {
+    }
+    fn f(_: std::vec::IntoIter<i32>) {}
+
+    a(vec![1, 2].into_iter());
+    b(vec![1, 2].into_iter());
+    c(vec![1, 2].into_iter());
+    d(vec![1, 2].into_iter());
+    b([&1, &2, &3].into_iter().cloned());
+
+    b(vec![1, 2].into_iter().into_iter());
+    b(vec![1, 2].into_iter().into_iter().into_iter());
+
+    macro_rules! macro_generated {
+        () => {
+            vec![1, 2].into_iter()
+        };
+    }
+    b(macro_generated!());
+}
+
 #[derive(Copy, Clone)]
 struct Foo<const C: char>;
 

tests/ui/useless_conversion.stderr

@@ -118,5 +118,65 @@ error: useless conversion to the same type: `std::vec::IntoIter<Foo<'a'>>`
 LL |     let _ = vec![s4, s4, s4].into_iter().into_iter();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![s4, s4, s4].into_iter()`
 
-error: aborting due to 19 previous errors
+error: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
+  --> $DIR/useless_conversion.rs:171:7
+   |
+LL |     b(vec![1, 2].into_iter());
+   |       ^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2]`
+   |
+note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
+  --> $DIR/useless_conversion.rs:161:13
+   |
+LL |     fn b<T: IntoIterator<Item = i32>>(_: T) {}
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
+  --> $DIR/useless_conversion.rs:172:7
+   |
+LL |     c(vec![1, 2].into_iter());
+   |       ^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2]`
+   |
+note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
+  --> $DIR/useless_conversion.rs:162:18
+   |
+LL |     fn c(_: impl IntoIterator<Item = i32>) {}
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
+  --> $DIR/useless_conversion.rs:173:7
+   |
+LL |     d(vec![1, 2].into_iter());
+   |       ^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2]`
+   |
+note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
+  --> $DIR/useless_conversion.rs:165:12
+   |
+LL |         T: IntoIterator<Item = i32>,
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
+  --> $DIR/useless_conversion.rs:176:7
+   |
+LL |     b(vec![1, 2].into_iter().into_iter());
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2]`
+   |
+note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
+  --> $DIR/useless_conversion.rs:161:13
+   |
+LL |     fn b<T: IntoIterator<Item = i32>>(_: T) {}
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit call to `.into_iter()` in function argument accepting `IntoIterator`
+  --> $DIR/useless_conversion.rs:177:7
+   |
+LL |     b(vec![1, 2].into_iter().into_iter().into_iter());
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2]`
+   |
+note: this parameter accepts any `IntoIterator`, so you don't need to call `.into_iter()`
+  --> $DIR/useless_conversion.rs:161:13
+   |
+LL |     fn b<T: IntoIterator<Item = i32>>(_: T) {}
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 24 previous errors