mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

enum-variant-generic-args-pats-pass: harden + describe.

Browse Source
This commit is contained in:
Mazdak Farrokhzad 2019-06-09 06:13:11 +02:00
parent 86c74d3a86
commit ce48086293
1 changed files with 20 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
src/test/ui/type-alias-enum-variants/enum-variant-generic-args-pats-pass.rs
View File

@ -1,15 +1,23 @@
// run-pass
// Check that resolving, in the value namespace, to an `enum` variant
// through a type alias is well behaved in the presence of generics.
// We check for situations with:
// 1. a generic type `Alias<T>`, we can type-apply `Alias` when referring to a variant.
// 2. a monotype `AliasFixed` of generic `Enum<T>`, we can refer to variants
// and the type-application of `T` in `AliasFixed` is kept.
#![allow(irrefutable_let_patterns)]
#[allow(dead_code)]
enum Enum<T> { TSVariant(T), SVariant { v: T } }
enum Enum<T> { TSVariant(T), SVariant { v: T }, UVariant }
type Alias<T> = Enum<T>;
type AliasFixed = Enum<()>;
macro_rules! is_variant {
(TSVariant, $expr:expr) => (is_variant!(@check TSVariant, (_), $expr));
(SVariant, $expr:expr) => (is_variant!(@check SVariant, { v: _ }, $expr));
(UVariant, $expr:expr) => (is_variant!(@check UVariant, {}, $expr));
(@check $variant:ident, $matcher:tt, $expr:expr) => (
assert!(if let Enum::$variant::<()> $matcher = $expr { true } else { false },
"expr does not have correct type");
@ -38,4 +46,15 @@ fn main() {
is_variant!(SVariant, Alias::<()>::SVariant { v: () });
is_variant!(SVariant, AliasFixed::SVariant { v: () });
// Unit variant
is_variant!(UVariant, Enum::UVariant);
is_variant!(UVariant, Enum::UVariant::<()>);
is_variant!(UVariant, Enum::<()>::UVariant);
is_variant!(UVariant, Alias::UVariant);
is_variant!(UVariant, Alias::<()>::UVariant);
is_variant!(UVariant, AliasFixed::UVariant);
}