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#![deny(dead_code)]
struct S {
f: i32, //~ ERROR: field is never read
sub: Sub, //~ ERROR: field is never read
}
struct Sub {
f: i32, //~ ERROR: field is never read
}
fn field_write(s: &mut S) {
s.f = 1;
s.sub.f = 2;
}
fn main() {
let mut s = S { f: 0, sub: Sub { f: 0 } };
field_write(&mut s);
auto_deref();
nested_boxes();
}
fn auto_deref() {
struct E {
x: bool,
y: bool, //~ ERROR: field is never read
}
struct P<'a> {
e: &'a mut E
}
impl P<'_> {
fn f(&mut self) {
self.e.x = true;
self.e.y = true;
}
}
let mut e = E { x: false, y: false };
let mut p = P { e: &mut e };
p.f();
assert!(e.x);
}
fn nested_boxes() {
struct A {
b: Box<B>,
}
struct B {
c: Box<C>,
}
struct C {
u: u32, //~ ERROR: field is never read
v: u32, //~ ERROR: field is never read
}
let mut a = A {
b: Box::new(B {
c: Box::new(C { u: 0, v: 0 }),
}),
};
a.b.c.v = 10;
a.b.c = Box::new(C { u: 1, v: 2 });
}
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