rust/tests/ui/rfcs/rfc-2008-non-exhaustive/uninhabited/coercions.rs

39 lines
845 B
Rust

//@ aux-build:uninhabited.rs
#![feature(never_type)]
extern crate uninhabited;
use uninhabited::{
UninhabitedEnum,
UninhabitedStruct,
UninhabitedTupleStruct,
UninhabitedVariants,
};
// This test checks that uninhabited non-exhaustive types cannot coerce to any type, as the never
// type can.
struct A;
fn can_coerce_never_type_to_anything(x: !) -> A {
x
}
fn cannot_coerce_empty_enum_to_anything(x: UninhabitedEnum) -> A {
x //~ ERROR mismatched types
}
fn cannot_coerce_empty_tuple_struct_to_anything(x: UninhabitedTupleStruct) -> A {
x //~ ERROR mismatched types
}
fn cannot_coerce_empty_struct_to_anything(x: UninhabitedStruct) -> A {
x //~ ERROR mismatched types
}
fn cannot_coerce_enum_with_empty_variants_to_anything(x: UninhabitedVariants) -> A {
x //~ ERROR mismatched types
}
fn main() {}