src/test/ui/rfc-2008-non-exhaustive/uninhabited/patterns_same_crate.rs

   1 #![deny(unreachable_patterns)]
   2 #![feature(exhaustive_patterns)]
   3 #![feature(never_type)]
   4
   5 #[non_exhaustive]
   6 pub enum UninhabitedEnum {
   7 }
   8
   9 #[non_exhaustive]
  10 pub struct UninhabitedTupleStruct(!);
  11
  12 #[non_exhaustive]
  13 pub struct UninhabitedStruct {
  14     _priv: !,
  15 }
  16
  17 pub enum UninhabitedVariants {
  18     #[non_exhaustive] Tuple(!),
  19     #[non_exhaustive] Struct { x: ! }
  20 }
  21
  22 pub enum PartiallyInhabitedVariants {
  23     Tuple(u8),
  24     #[non_exhaustive] Struct { x: ! }
  25 }
  26
  27 fn uninhabited_enum() -> Option<UninhabitedEnum> {
  28     None
  29 }
  30
  31 fn uninhabited_variant() -> Option<UninhabitedVariants> {
  32     None
  33 }
  34
  35 fn partially_inhabited_variant() -> PartiallyInhabitedVariants {
  36     PartiallyInhabitedVariants::Tuple(3)
  37 }
  38
  39 fn uninhabited_struct() -> Option<UninhabitedStruct> {
  40     None
  41 }
  42
  43 fn uninhabited_tuple_struct() -> Option<UninhabitedTupleStruct> {
  44     None
  45 }
  46
  47 // This test checks that non-exhaustive types that would normally be considered uninhabited within
  48 // the defining crate are still considered uninhabited.
  49
  50 fn main() {
  51     match uninhabited_enum() {
  52         Some(_x) => (), //~ ERROR unreachable pattern
  53         None => (),
  54     }
  55
  56     match uninhabited_variant() {
  57         Some(_x) => (), //~ ERROR unreachable pattern
  58         None => (),
  59     }
  60
  61     while let PartiallyInhabitedVariants::Struct { x } = partially_inhabited_variant() {
  62         //~^ ERROR unreachable pattern
  63     }
  64
  65     while let Some(_x) = uninhabited_struct() { //~ ERROR unreachable pattern
  66     }
  67
  68     while let Some(_x) = uninhabited_tuple_struct() { //~ ERROR unreachable pattern
  69     }
  70 }