Only borrow place for matching under specific conditions

src/test/ui/closures/2229_closure_analysis/run_pass/lit-pattern-matching-with-methods.rs

@@ -0,0 +1,24 @@
+//check-pass
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+#![warn(unused)]
+#![feature(rustc_attrs)]
+#![feature(btree_drain_filter)]
+
+use std::collections::BTreeMap;
+use std::panic::{catch_unwind, AssertUnwindSafe};
+
+fn main() {
+    let mut map = BTreeMap::new();
+    map.insert("a", ());
+    map.insert("b", ());
+    map.insert("c", ());
+
+    {
+        let mut it = map.drain_filter(|_, _| true);
+        catch_unwind(AssertUnwindSafe(|| while it.next().is_some() {})).unwrap_err();
+        let result = catch_unwind(AssertUnwindSafe(|| it.next()));
+        assert!(matches!(result, Ok(None)));
+    }
+
+}

src/test/ui/closures/2229_closure_analysis/run_pass/lit-pattern-matching-with-methods.stderr

@@ -0,0 +1,11 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/lit-pattern-matching-with-methods.rs:2:12
+   |
+LL | #![feature(capture_disjoint_fields)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #53488 <https://github.com/rust-lang/rust/issues/53488> for more information
+
+warning: 1 warning emitted
+

src/test/ui/closures/2229_closure_analysis/run_pass/struct-pattern-matching-with-methods.rs

@@ -0,0 +1,48 @@
+//check-pass
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+#![warn(unused)]
+#![feature(rustc_attrs)]
+
+#[derive(Debug, Clone, Copy)]
+enum PointType {
+    TwoD { x: u32, y: u32 },
+
+    ThreeD{ x: u32, y: u32, z: u32 }
+}
+
+struct Points {
+    points: Vec<PointType>,
+}
+
+impl Points {
+    pub fn test1(&mut self) -> Vec<usize> {
+        (0..self.points.len())
+            .filter_map(|i| {
+                let idx = i as usize;
+                match self.test2(idx) {
+                    PointType::TwoD { .. } => Some(i),
+                    PointType::ThreeD { .. } => None,
+                }
+            })
+            .collect()
+    }
+
+    pub fn test2(&mut self, i: usize) -> PointType {
+        self.points[i]
+    }
+}
+
+fn main() {
+    let mut points = Points {
+        points: Vec::<PointType>::new()
+    };
+
+    points.points.push(PointType::ThreeD { x:0, y:0, z:0 });
+    points.points.push(PointType::TwoD{ x:0, y:0 });
+    points.points.push(PointType::ThreeD{ x:0, y:0, z:0 });
+    points.points.push(PointType::TwoD{ x:0, y:0 });
+
+    println!("{:?}", points.test1());
+    println!("{:?}", points.points);
+}

src/test/ui/closures/2229_closure_analysis/run_pass/struct-pattern-matching-with-methods.stderr

@@ -0,0 +1,11 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/struct-pattern-matching-with-methods.rs:2:12
+   |
+LL | #![feature(capture_disjoint_fields)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #53488 <https://github.com/rust-lang/rust/issues/53488> for more information
+
+warning: 1 warning emitted
+

src/test/ui/closures/2229_closure_analysis/run_pass/tuple-struct-pattern-matching-with-methods.rs

@@ -0,0 +1,43 @@
+//check-pass
+#![feature(capture_disjoint_fields)]
+//~^ WARNING: the feature `capture_disjoint_fields` is incomplete
+
+#[derive(Copy, Clone)]
+enum PointType {
+    TwoD(u32, u32),
+    ThreeD(u32, u32, u32)
+}
+
+struct Points {
+    points: Vec<PointType>,
+}
+
+impl Points {
+    pub fn test1(&mut self) -> Vec<usize> {
+        (0..self.points.len())
+            .filter_map(|i| {
+                match self.test2(i) {
+                    PointType::TwoD (..) => Some(i),
+                    PointType::ThreeD (..) => None,
+                }
+            })
+            .collect()
+    }
+
+    pub fn test2(&mut self, i: usize) -> PointType {
+        self.points[i]
+    }
+}
+
+fn main() {
+    let mut points = Points {
+        points: Vec::<PointType>::new()
+    };
+
+    points.points.push(PointType::ThreeD(0,0,0));
+    points.points.push(PointType::TwoD(0,0));
+    points.points.push(PointType::ThreeD(0,0,1));
+    points.points.push(PointType::TwoD(0,1));
+
+    println!("{:?}", points.test1());
+}

src/test/ui/closures/2229_closure_analysis/run_pass/tuple-struct-pattern-matching-with-methods.stderr

@@ -0,0 +1,11 @@
+warning: the feature `capture_disjoint_fields` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/tuple-struct-pattern-matching-with-methods.rs:2:12
+   |
+LL | #![feature(capture_disjoint_fields)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #53488 <https://github.com/rust-lang/rust/issues/53488> for more information
+
+warning: 1 warning emitted
+