error[E0500]: closure requires unique access to `x` but it is already borrowed --> $DIR/borrowck-closures-unique.rs:26:14 | LL | let c1 = || get(x); | -- - first borrow occurs due to use of `x` in closure | | | borrow occurs here LL | let c2 = || set(x); | ^^ - second borrow occurs due to use of `x` in closure | | | closure construction occurs here LL | c1; | -- first borrow later used here error[E0500]: closure requires unique access to `x` but it is already borrowed --> $DIR/borrowck-closures-unique.rs:32:14 | LL | let c1 = || get(x); | -- - first borrow occurs due to use of `x` in closure | | | borrow occurs here LL | let c2 = || { get(x); set(x); }; | ^^ - second borrow occurs due to use of `x` in closure | | | closure construction occurs here LL | c1; | -- first borrow later used here error[E0524]: two closures require unique access to `x` at the same time --> $DIR/borrowck-closures-unique.rs:38:14 | LL | let c1 = || set(x); | -- - first borrow occurs due to use of `x` in closure | | | first closure is constructed here LL | let c2 = || set(x); | ^^ - second borrow occurs due to use of `x` in closure | | | second closure is constructed here LL | c1; | -- first borrow later used here error[E0594]: cannot assign to `x`, as it is not declared as mutable --> $DIR/borrowck-closures-unique.rs:43:38 | LL | fn e(x: &'static mut isize) { | - help: consider changing this to be mutable: `mut x` LL | let c1 = |y: &'static mut isize| x = y; | ^^^^^ cannot assign error: aborting due to 4 previous errors Some errors have detailed explanations: E0500, E0524, E0594. For more information about an error, try `rustc --explain E0500`.