moved renamed docs formatted | cannot-mutate-captured-non-mut-var.rs

Author: Kivooeo

tests/ui/cannot-mutate-captured-non-mut-var.rs

@@ -0,0 +1,23 @@
+//! Tests errors for mutating captured immutable variables in closures.
+
+#![feature(unboxed_closures, tuple_trait)]
+
+use std::io::Read;
+
+fn to_fn_once<A: std::marker::Tuple, F: FnOnce<A>>(f: F) -> F {
+    f
+}
+
+fn main() {
+    let x = 1;
+    to_fn_once(move || {
+        x = 2;
+        //~^ ERROR: cannot assign to `x`, as it is not declared as mutable
+    });
+
+    let s = std::io::stdin();
+    to_fn_once(move || {
+        s.read_to_end(&mut Vec::new());
+        //~^ ERROR: cannot borrow `s` as mutable, as it is not declared as mutable
+    });
+}