src/test/ui/consts/qualif-indirect-mutation-fail.rs

   1 // compile-flags: --crate-type=lib
   2 #![feature(const_mut_refs)]
   3 #![feature(const_precise_live_drops)]
   4 #![feature(const_swap)]
   5 #![feature(raw_ref_op)]
   6
   7 // Mutable borrow of a field with drop impl.
   8 pub const fn f() {
   9     let mut a: (u32, Option<String>) = (0, None); //~ ERROR destructor of
  10     let _ = &mut a.1;
  11 }
  12
  13 // Mutable borrow of a type with drop impl.
  14 pub const A1: () = {
  15     let mut x = None; //~ ERROR destructor of
  16     let mut y = Some(String::new());
  17     let a = &mut x;
  18     let b = &mut y;
  19     std::mem::swap(a, b);
  20     std::mem::forget(y);
  21 };
  22
  23 // Mutable borrow of a type with drop impl.
  24 pub const A2: () = {
  25     let mut x = None;
  26     let mut y = Some(String::new());
  27     let a = &mut x;
  28     let b = &mut y;
  29     std::mem::swap(a, b);
  30     std::mem::forget(y);
  31     let _z = x; //~ ERROR destructor of
  32 };
  33
  34 // Shared borrow of a type that might be !Freeze and Drop.
  35 pub const fn g1<T>() {
  36     let x: Option<T> = None; //~ ERROR destructor of
  37     let _ = x.is_some();
  38 }
  39
  40 // Shared borrow of a type that might be !Freeze and Drop.
  41 pub const fn g2<T>() {
  42     let x: Option<T> = None;
  43     let _ = x.is_some();
  44     let _y = x; //~ ERROR destructor of
  45 }
  46
  47 // Mutable raw reference to a Drop type.
  48 pub const fn address_of_mut() {
  49     let mut x: Option<String> = None; //~ ERROR destructor of
  50     &raw mut x;
  51
  52     let mut y: Option<String> = None; //~ ERROR destructor of
  53     std::ptr::addr_of_mut!(y);
  54 }
  55
  56 // Const raw reference to a Drop type. Conservatively assumed to allow mutation
  57 // until resolution of https://github.com/rust-lang/rust/issues/56604.
  58 pub const fn address_of_const() {
  59     let x: Option<String> = None; //~ ERROR destructor of
  60     &raw const x;
  61
  62     let y: Option<String> = None; //~ ERROR destructor of
  63     std::ptr::addr_of!(y);
  64 }