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-rw-r--r--src/test/ui/array-slice-vec/subslice-patterns-const-eval.rs95
1 files changed, 95 insertions, 0 deletions
diff --git a/src/test/ui/array-slice-vec/subslice-patterns-const-eval.rs b/src/test/ui/array-slice-vec/subslice-patterns-const-eval.rs
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index 000000000..0b793fa01
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+++ b/src/test/ui/array-slice-vec/subslice-patterns-const-eval.rs
@@ -0,0 +1,95 @@
+// Test that array subslice patterns are correctly handled in const evaluation.
+
+// run-pass
+
+#[derive(PartialEq, Debug, Clone)]
+struct N(u8);
+
+#[derive(PartialEq, Debug, Clone)]
+struct Z;
+
+macro_rules! n {
+ ($($e:expr),* $(,)?) => {
+ [$(N($e)),*]
+ }
+}
+
+// This macro has an unused variable so that it can be repeated base on the
+// number of times a repeated variable (`$e` in `z`) occurs.
+macro_rules! zed {
+ ($e:expr) => { Z }
+}
+
+macro_rules! z {
+ ($($e:expr),* $(,)?) => {
+ [$(zed!($e)),*]
+ }
+}
+
+// Compare constant evaluation and runtime evaluation of a given expression.
+macro_rules! compare_evaluation {
+ ($e:expr, $t:ty $(,)?) => {{
+ const CONST_EVAL: $t = $e;
+ const fn const_eval() -> $t { $e }
+ static CONST_EVAL2: $t = const_eval();
+ let runtime_eval = $e;
+ assert_eq!(CONST_EVAL, runtime_eval);
+ assert_eq!(CONST_EVAL2, runtime_eval);
+ }}
+}
+
+// Repeat `$test`, substituting the given macro variables with the given
+// identifiers.
+//
+// For example:
+//
+// repeat! {
+// ($name); X; Y:
+// struct $name;
+// }
+//
+// Expands to:
+//
+// struct X; struct Y;
+//
+// This is used to repeat the tests using both the `N` and `Z`
+// types.
+macro_rules! repeat {
+ (($($dollar:tt $placeholder:ident)*); $($($values:ident),+);*: $($test:tt)*) => {
+ macro_rules! single {
+ ($($dollar $placeholder:ident),*) => { $($test)* }
+ }
+ $(single!($($values),+);)*
+ }
+}
+
+fn main() {
+ repeat! {
+ ($arr $Ty); n, N; z, Z:
+ compare_evaluation!({ let [_, x @ .., _] = $arr!(1, 2, 3, 4); x }, [$Ty; 2]);
+ compare_evaluation!({ let [_, ref x @ .., _] = $arr!(1, 2, 3, 4); x }, &'static [$Ty; 2]);
+ compare_evaluation!({ let [_, x @ .., _] = &$arr!(1, 2, 3, 4); x }, &'static [$Ty; 2]);
+
+ compare_evaluation!({ let [_, _, x @ .., _, _] = $arr!(1, 2, 3, 4); x }, [$Ty; 0]);
+ compare_evaluation!(
+ { let [_, _, ref x @ .., _, _] = $arr!(1, 2, 3, 4); x },
+ &'static [$Ty; 0],
+ );
+ compare_evaluation!(
+ { let [_, _, x @ .., _, _] = &$arr!(1, 2, 3, 4); x },
+ &'static [$Ty; 0],
+ );
+
+ compare_evaluation!({ let [_, .., x] = $arr!(1, 2, 3, 4); x }, $Ty);
+ compare_evaluation!({ let [_, .., ref x] = $arr!(1, 2, 3, 4); x }, &'static $Ty);
+ compare_evaluation!({ let [_, _y @ .., x] = &$arr!(1, 2, 3, 4); x }, &'static $Ty);
+ }
+
+ compare_evaluation!({ let [_, .., N(x)] = n!(1, 2, 3, 4); x }, u8);
+ compare_evaluation!({ let [_, .., N(ref x)] = n!(1, 2, 3, 4); x }, &'static u8);
+ compare_evaluation!({ let [_, .., N(x)] = &n!(1, 2, 3, 4); x }, &'static u8);
+
+ compare_evaluation!({ let [N(x), .., _] = n!(1, 2, 3, 4); x }, u8);
+ compare_evaluation!({ let [N(ref x), .., _] = n!(1, 2, 3, 4); x }, &'static u8);
+ compare_evaluation!({ let [N(x), .., _] = &n!(1, 2, 3, 4); x }, &'static u8);
+}