builtin derive macros: fix error with const generics default

This commit is contained in:
Soveu 2021-04-16 16:29:11 +02:00
parent d4bc912c48
commit 9ecfae44d7
2 changed files with 27 additions and 2 deletions

View File

@ -541,7 +541,7 @@ impl<'a> TraitDef<'a> {
self.generics.to_generics(cx, self.span, type_ident, generics);
// Create the generic parameters
params.extend(generics.params.iter().map(|param| match param.kind {
params.extend(generics.params.iter().map(|param| match &param.kind {
GenericParamKind::Lifetime { .. } => param.clone(),
GenericParamKind::Type { .. } => {
// I don't think this can be moved out of the loop, since
@ -561,7 +561,18 @@ impl<'a> TraitDef<'a> {
cx.typaram(self.span, param.ident, vec![], bounds, None)
}
GenericParamKind::Const { .. } => param.clone(),
GenericParamKind::Const { ty, kw_span, .. } => {
let const_nodefault_kind = GenericParamKind::Const {
ty: ty.clone(),
kw_span: kw_span.clone(),
// We can't have default values inside impl block
default: None,
};
let mut param_clone = param.clone();
param_clone.kind = const_nodefault_kind;
param_clone
}
}));
// and similarly for where clauses

View File

@ -0,0 +1,14 @@
// check-pass
#![allow(incomplete_features)]
#![feature(const_generics_defaults)]
#[derive(Clone, PartialEq, Debug)]
struct Example<T, const N: usize = 1usize>([T; N]);
fn main() {
let a = Example([(); 16]);
let b = a.clone();
if a != b {
let _c = format!("{:?}", a);
}
}