Rollup merge of #60550 - skinny121:concrete_const_tests, r=varkor

Add tests for concrete const types

In response to the request for help in https://github.com/rust-lang/rust/issues/44580#issuecomment-488819344, I have added several ui tests around the use of concrete const types, i.e. A<2>.

r? @varkor

4 files changed, 50 insertions, 0 deletions

diff --git a/src/test/ui/const-generics/concrete-const-as-fn-arg.rs b/src/test/ui/const-generics/concrete-const-as-fn-arg.rs
new file mode 100644
index 00000000000..54981b77a2b
--- /dev/null
+++ b/src/test/ui/const-generics/concrete-const-as-fn-arg.rs
@@ -0,0 +1,14 @@
+// Test that a concrete const type i.e. A<2>, can be used as an argument type in a function
+// run-pass
+
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+struct A<const N: usize>; // ok
+
+fn with_concrete_const_arg(_: A<2>) -> u32 { 17 }
+
+fn main() {
+    let val: A<2> = A;
+    assert_eq!(with_concrete_const_arg(val), 17);
+}
diff --git a/src/test/ui/const-generics/concrete-const-as-fn-arg.stderr b/src/test/ui/const-generics/concrete-const-as-fn-arg.stderr
new file mode 100644
index 00000000000..955b319d700
--- /dev/null
+++ b/src/test/ui/const-generics/concrete-const-as-fn-arg.stderr
@@ -0,0 +1,6 @@
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+  --> $DIR/concrete-const-as-fn-arg.rs:4:12
+   |
+LL | #![feature(const_generics)]
+   |            ^^^^^^^^^^^^^^
+
diff --git a/src/test/ui/const-generics/concrete-const-impl-method.rs b/src/test/ui/const-generics/concrete-const-impl-method.rs
new file mode 100644
index 00000000000..226ea415180
--- /dev/null
+++ b/src/test/ui/const-generics/concrete-const-impl-method.rs
@@ -0,0 +1,24 @@
+// Test that a method/associated non-method within an impl block of a concrete const type i.e. A<2>,
+// is callable.
+// run-pass
+
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+pub struct A<const N: u32>;
+
+impl A<2> {
+    fn impl_method(&self) -> u32 {
+        17
+    }
+
+    fn associated_non_method() -> u32 {
+        17
+    }
+}
+
+fn main() {
+    let val: A<2> = A;
+    assert_eq!(val.impl_method(), 17);
+    assert_eq!(A::<2>::associated_non_method(), 17);
+}
diff --git a/src/test/ui/const-generics/concrete-const-impl-method.stderr b/src/test/ui/const-generics/concrete-const-impl-method.stderr
new file mode 100644
index 00000000000..3ce488c6275
--- /dev/null
+++ b/src/test/ui/const-generics/concrete-const-impl-method.stderr
@@ -0,0 +1,6 @@
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+  --> $DIR/concrete-const-impl-method.rs:5:12
+   |
+LL | #![feature(const_generics)]
+   |            ^^^^^^^^^^^^^^
+