Add has_default to GenericParamDefKind::Const

This currently creates a field which is always false on GenericParamDefKind for future use when
consts are permitted to have defaults

Update const_generics:default locations

Previously just ignored them, now actually do something about them.

Fix using type check instead of value

Add parsing

This adds all the necessary changes to lower const-generics defaults from parsing.

Change P<Expr> to AnonConst

This matches the arguments passed to instantiations of const generics, and makes it specific to
just anonymous constants.

Attempt to fix lowering bugs

1 files changed, 15 insertions, 0 deletions

diff --git a/src/test/ui/const-generics/defaults/const-default.rs b/src/test/ui/const-generics/defaults/const-default.rs
new file mode 100644
index 00000000000..b2286e7d5bd
--- /dev/null
+++ b/src/test/ui/const-generics/defaults/const-default.rs
@@ -0,0 +1,15 @@
+// check-pass
+
+#![feature(const_generics)]
+#![feature(const_generic_defaults)]
+#![allow(incomplete_features)]
+
+
+#[derive(Default)]
+pub struct ConstDefault<const N: usize = 3> {
+  items: [u32; N]
+}
+
+pub fn main() {
+  let s = ConstDefault::default();
+}