moved renamed docs formatted | last-use-in-block.rs

Author: Kivooeo

tests/ui/closures/closure-last-use-move.rs

@@ -0,0 +1,33 @@
+//! Regression test for issue #1818
+//! last-use analysis in closures should allow moves instead of requiring copies.
+//!
+//! The original issue was that the compiler incorrectly flagged certain return values
+//! in anonymous functions/closures as requiring copies of non-copyable values, when
+//! they should have been treated as moves (since they were the last use of the value).
+//!
+//! See: https://github.com/rust-lang/rust/issues/1818
+
+//@ run-pass
+
+fn apply<T, F>(s: String, mut f: F) -> T 
+where 
+    F: FnMut(String) -> T 
+{
+    fn g<T, F>(s: String, mut f: F) -> T 
+    where 
+        F: FnMut(String) -> T 
+    {
+        f(s)
+    }
+    
+    g(s, |v| {
+        let r = f(v);
+        r // This should be a move, not requiring copy
+    })
+}
+
+pub fn main() {
+    // Actually test the functionality
+    let result = apply(String::from("test"), |s| s.len());
+    assert_eq!(result, 4);
+}