add const_param_ty_unchecked gate

2026-05-29 20:46:07 +03:00 · 2026-03-07 10:18:35 +01:00
parent 57cb10ae1e
commit 35bc5436d3
10 changed files with 192 additions and 7 deletions
@@ -0,0 +1,19 @@
+//! Ensure we don't allow Vec<[u8]> as const parameter even with
+//! `const_param_ty_unchecked` feature.
+#![allow(incomplete_features)]
+#![feature(adt_const_params, const_param_ty_unchecked, const_param_ty_trait)]
+use std::marker::ConstParamTy_;
+
+struct VectorOfBytes {
+    a: Vec<[u8]>
+    //~^ ERROR: the size for values of type `[u8]` cannot be known at compilation time [E0277]
+}
+impl ConstParamTy_ for VectorOfBytes {}
+
+fn bar<const N: VectorOfBytes>() {}
+fn foo<const N: Vec<[u8]>>() {}
+    //~^ ERROR: the size for values of type `[u8]` cannot be known at compilation time [E0277]
+    //~| ERROR: the size for values of type `[u8]` cannot be known at compilation time [E0277]
+
+
+fn main() {}
@@ -0,0 +1,34 @@
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> $DIR/const_param_ty_unchecked-unsupported.rs:8:8
+   |
+LL |     a: Vec<[u8]>
+   |        ^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `[u8]`
+note: required by an implicit `Sized` bound in `Vec`
+  --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> $DIR/const_param_ty_unchecked-unsupported.rs:14:8
+   |
+LL | fn foo<const N: Vec<[u8]>>() {}
+   |        ^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `[u8]`
+note: required by an implicit `Sized` bound in `Vec`
+  --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> $DIR/const_param_ty_unchecked-unsupported.rs:14:8
+   |
+LL | fn foo<const N: Vec<[u8]>>() {}
+   |        ^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `[u8]`
+note: required by an implicit `Sized` bound in `Vec`
+  --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
@@ -0,0 +1,26 @@
+//@run-pass
+//! Ensure that const_param_ty_unchecked gate allow
+//! bypassing `ConstParamTy_` implementation check
+
+#![allow(dead_code, incomplete_features)]
+#![feature(const_param_ty_unchecked, const_param_ty_trait)]
+
+use std::marker::ConstParamTy_;
+
+struct Miow;
+
+struct Meoww(Miow);
+
+struct Float {
+    float: f32,
+}
+
+impl ConstParamTy_ for Meoww {}
+impl ConstParamTy_ for Float {}
+
+fn something2<const N: *mut u8>() {}
+fn something<const N: f64>(a: f64) -> f64 {
+    N + a
+}
+
+fn main() {}
@@ -0,0 +1,31 @@
+// gate-test-const_param_ty_unchecked
+//! Ensure this fails when const_param_ty_unchecked isn't used
+#![allow(incomplete_features)]
+#![feature(const_param_ty_trait)]
+
+use std::marker::ConstParamTy_;
+
+struct Miow;
+
+struct Meoww(Miow);
+
+struct Float {
+    float: f32,
+}
+
+impl ConstParamTy_ for Meoww {}
+                    //~^ ERROR: the trait `ConstParamTy_` cannot be implemented for this type [E0204]
+impl ConstParamTy_ for Float {}
+                    //~^ ERROR: the trait `ConstParamTy_` cannot be implemented for this type [E0204]
+
+fn something2<const N: *mut u8>() {}
+                   //~^ ERROR: using raw pointers as const generic parameters is forbidden
+fn something<const N: f64>(a: f64) -> f64 {
+                   //~^ ERROR: `f64` is forbidden as the type of a const generic parameter
+    N + a
+}
+fn foo<const N: Vec<[u8]>>() {}
+    //~^  ERROR: the size for values of type `[u8]` cannot be known at compilation time [E0277]
+          //~^^ ERROR: `Vec<[u8]>` is forbidden as the type of a const generic parameter
+
+fn main() {}
@@ -0,0 +1,56 @@
+error[E0204]: the trait `ConstParamTy_` cannot be implemented for this type
+  --> $DIR/const_param_ty_unchecked_fail.rs:16:24
+   |
+LL | struct Meoww(Miow);
+   |              ---- this field does not implement `ConstParamTy_`
+...
+LL | impl ConstParamTy_ for Meoww {}
+   |                        ^^^^^
+
+error[E0204]: the trait `ConstParamTy_` cannot be implemented for this type
+  --> $DIR/const_param_ty_unchecked_fail.rs:18:24
+   |
+LL |     float: f32,
+   |     ---------- this field does not implement `ConstParamTy_`
+...
+LL | impl ConstParamTy_ for Float {}
+   |                        ^^^^^
+
+error: using raw pointers as const generic parameters is forbidden
+  --> $DIR/const_param_ty_unchecked_fail.rs:21:24
+   |
+LL | fn something2<const N: *mut u8>() {}
+   |                        ^^^^^^^
+   |
+   = note: the only supported types are integers, `bool`, and `char`
+
+error: `f64` is forbidden as the type of a const generic parameter
+  --> $DIR/const_param_ty_unchecked_fail.rs:23:23
+   |
+LL | fn something<const N: f64>(a: f64) -> f64 {
+   |                       ^^^
+   |
+   = note: the only supported types are integers, `bool`, and `char`
+
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> $DIR/const_param_ty_unchecked_fail.rs:27:8
+   |
+LL | fn foo<const N: Vec<[u8]>>() {}
+   |        ^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `[u8]`
+note: required by an implicit `Sized` bound in `Vec`
+  --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
+
+error: `Vec<[u8]>` is forbidden as the type of a const generic parameter
+  --> $DIR/const_param_ty_unchecked_fail.rs:27:17
+   |
+LL | fn foo<const N: Vec<[u8]>>() {}
+   |                 ^^^^^^^^^
+   |
+   = note: the only supported types are integers, `bool`, and `char`
+
+error: aborting due to 6 previous errors
+
+Some errors have detailed explanations: E0204, E0277.
+For more information about an error, try `rustc --explain E0204`.