diff options
| -rw-r--r-- | src/librustc_ast_passes/ast_validation.rs | 25 | ||||
| -rw-r--r-- | src/test/ui/const-generics/const-fn-with-const-param.rs | 4 | ||||
| -rw-r--r-- | src/test/ui/const-generics/const-fn-with-const-param.stderr | 17 |
3 files changed, 5 insertions, 41 deletions
diff --git a/src/librustc_ast_passes/ast_validation.rs b/src/librustc_ast_passes/ast_validation.rs index 9563325fe32..395fd746085 100644 --- a/src/librustc_ast_passes/ast_validation.rs +++ b/src/librustc_ast_passes/ast_validation.rs @@ -561,28 +561,6 @@ impl<'a> AstValidator<'a> { } } - /// We currently do not permit const generics in `const fn`, - /// as this is tantamount to allowing compile-time dependent typing. - /// - /// FIXME(const_generics): Is this really true / necessary? Discuss with @varkor. - /// At any rate, the restriction feels too syntactic. Consider moving it to e.g. typeck. - fn check_const_fn_const_generic(&self, span: Span, sig: &FnSig, generics: &Generics) { - if let Const::Yes(const_span) = sig.header.constness { - // Look for const generics and error if we find any. - for param in &generics.params { - if let GenericParamKind::Const { .. } = param.kind { - self.err_handler() - .struct_span_err( - span, - "const parameters are not permitted in const functions", - ) - .span_label(const_span, "`const` because of this") - .emit(); - } - } - } - } - fn check_item_named(&self, ident: Ident, kind: &str) { if ident.name != kw::Underscore { return; @@ -966,9 +944,8 @@ impl<'a> Visitor<'a> for AstValidator<'a> { .emit(); } } - ItemKind::Fn(def, ref sig, ref generics, ref body) => { + ItemKind::Fn(def, _, _, ref body) => { self.check_defaultness(item.span, def); - self.check_const_fn_const_generic(item.span, sig, generics); if body.is_none() { let msg = "free function without a body"; diff --git a/src/test/ui/const-generics/const-fn-with-const-param.rs b/src/test/ui/const-generics/const-fn-with-const-param.rs index e9e236be556..3d8b77bcf7b 100644 --- a/src/test/ui/const-generics/const-fn-with-const-param.rs +++ b/src/test/ui/const-generics/const-fn-with-const-param.rs @@ -1,11 +1,11 @@ +// run-pass #![feature(const_generics)] //~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash const fn const_u32_identity<const X: u32>() -> u32 { - //~^ ERROR const parameters are not permitted in const functions X } fn main() { - println!("{:?}", const_u32_identity::<18>()); + assert_eq!(const_u32_identity::<18>(), 18); } diff --git a/src/test/ui/const-generics/const-fn-with-const-param.stderr b/src/test/ui/const-generics/const-fn-with-const-param.stderr index e944b02101e..64b9c18a8f5 100644 --- a/src/test/ui/const-generics/const-fn-with-const-param.stderr +++ b/src/test/ui/const-generics/const-fn-with-const-param.stderr @@ -1,23 +1,10 @@ -error: const parameters are not permitted in const functions - --> $DIR/const-fn-with-const-param.rs:4:1 - | -LL | const fn const_u32_identity<const X: u32>() -> u32 { - | ^---- - | | - | _`const` because of this - | | -LL | | -LL | | X -LL | | } - | |_^ - warning: the feature `const_generics` is incomplete and may cause the compiler to crash - --> $DIR/const-fn-with-const-param.rs:1:12 + --> $DIR/const-fn-with-const-param.rs:2:12 | LL | #![feature(const_generics)] | ^^^^^^^^^^^^^^ | = note: `#[warn(incomplete_features)]` on by default -error: aborting due to previous error; 1 warning emitted +warning: 1 warning emitted |