Merge pull request Rust-for-Linux#60 from Rust-for-Linux/dev/lifetime-test

tests: ui: add new tests for lifetime violations

Author: y86-dev

tests/ui/compile-fail/init/lifetime_violated.rs

@@ -0,0 +1,40 @@
+use pin_init::{init, InPlaceInit, Init};
+
+#[derive(Debug)]
+struct Foo {
+    a: i32,
+}
+
+impl Foo {
+    fn new(val: &i32) -> impl Init<Self> + use<'_> {
+        init!(Self { a: *val })
+    }
+}
+
+#[derive(Debug)]
+struct Bar {
+    foo: Foo,
+}
+
+impl Bar {
+    fn new(foo: impl Init<Foo>) -> impl Init<Self> {
+        init!(Self { foo <- foo })
+    }
+}
+
+fn main() {
+    // problematic:
+    let foo;
+    {
+        let val = 42;
+        foo = Foo::new(&val);
+    }
+    let bar = Box::init(Bar::new(foo));
+    println!("{bar:?}");
+
+    // okay:
+    let val = 42;
+    let foo = Foo::new(&val);
+    let bar = Box::init(Bar::new(foo));
+    println!("{bar:?}");
+}

tests/ui/compile-fail/init/lifetime_violated.stderr

@@ -0,0 +1,11 @@
+error[E0597]: `val` does not live long enough
+  --> tests/ui/compile-fail/init/lifetime_violated.rs:30:24
+   |
+29 |         let val = 42;
+   |             --- binding `val` declared here
+30 |         foo = Foo::new(&val);
+   |                        ^^^^ borrowed value does not live long enough
+31 |     }
+   |     - `val` dropped here while still borrowed
+32 |     let bar = Box::init(Bar::new(foo));
+   |                                  --- borrow later used here