#[warn(clippy::mixed_read_write_in_expression)] #[allow( unused_assignments, unused_variables, clippy::no_effect, dead_code, clippy::disallowed_names )] fn main() { let mut x = 0; let a = { x = 1; 1 } + x; //~^ ERROR: unsequenced read of `x` // Example from iss#277 x += { //~^ ERROR: unsequenced read of `x` x = 20; 2 }; // Does it work in weird places? // ...in the base for a struct expression? struct Foo { a: i32, b: i32, }; let base = Foo { a: 4, b: 5 }; let foo = Foo { a: x, //~^ ERROR: unsequenced read of `x` ..{ x = 6; base } }; // ...inside a closure? let closure = || { let mut x = 0; x += { //~^ ERROR: unsequenced read of `x` x = 20; 2 }; }; // ...not across a closure? let mut y = 0; let b = (y, || y = 1); // && and || evaluate left-to-right. let a = { x = 1; true } && (x == 3); let a = { x = 1; true } || (x == 3); // Make sure we don't get confused by alpha conversion. let a = { let mut x = 1; x = 2; 1 } + x; // No warning if we don't read the variable... x = { x = 20; 2 }; // ...if the assignment is in a closure... let b = { || { x = 1; }; 1 } + x; // ... or the access is under an address. let b = ( { let p = &x; 1 }, { x = 1; x }, ); // Limitation: l-values other than simple variables don't trigger // the warning. let mut tup = (0, 0); let c = { tup.0 = 1; 1 } + tup.0; // Limitation: you can get away with a read under address-of. let mut z = 0; let b = ( &{ z = x; x }, { x = 3; x }, ); } async fn issue_6925() { let _ = vec![async { true }.await, async { false }.await]; }