use hir::{CastError, ClosureStyle, HirDisplay};
use crate::{Diagnostic, DiagnosticCode, DiagnosticsContext};
macro_rules! format_ty {
($ctx:expr, $fmt:literal, $($arg:expr),* $(,)?) => {{
std::format!(
$fmt,
$(
$arg
.display($ctx.sema.db, $ctx.edition)
.with_closure_style(ClosureStyle::ClosureWithId)
),*
)
}}
}
pub(crate) fn invalid_cast(ctx: &DiagnosticsContext<'_>, d: &hir::InvalidCast) -> Diagnostic {
let display_range = ctx.sema.diagnostics_display_range(d.expr.map(|it| it.into()));
let (code, message) = match d.error {
CastError::CastToBool => (
DiagnosticCode::RustcHardError("E0054"),
format_ty!(ctx, "cannot cast `{}` as `bool`", d.expr_ty),
),
CastError::CastToChar => (
DiagnosticCode::RustcHardError("E0604"),
format_ty!(ctx, "only `u8` can be cast as `char`, not {}", d.expr_ty),
),
CastError::DifferingKinds => (
DiagnosticCode::RustcHardError("E0606"),
format_ty!(
ctx,
"casting `{}` as `{}` is invalid: vtable kinds may not match",
d.expr_ty,
d.cast_ty
),
),
CastError::SizedUnsizedCast => (
DiagnosticCode::RustcHardError("E0607"),
format_ty!(
ctx,
"cannot cast thin pointer `{}` to fat pointer `{}`",
d.expr_ty,
d.cast_ty
),
),
CastError::Unknown | CastError::IllegalCast => (
DiagnosticCode::RustcHardError("E0606"),
format_ty!(ctx, "casting `{}` as `{}` is invalid", d.expr_ty, d.cast_ty),
),
CastError::IntToFatCast => (
DiagnosticCode::RustcHardError("E0606"),
format_ty!(ctx, "cannot cast `{}` to a fat pointer `{}`", d.expr_ty, d.cast_ty),
),
CastError::NeedDeref => (
DiagnosticCode::RustcHardError("E0606"),
format_ty!(
ctx,
"casting `{}` as `{}` is invalid: needs dereference or removal of unneeded borrow",
d.expr_ty,
d.cast_ty
),
),
CastError::NeedViaPtr => (
DiagnosticCode::RustcHardError("E0606"),
format_ty!(
ctx,
"casting `{}` as `{}` is invalid: needs casting through a raw pointer first",
d.expr_ty,
d.cast_ty
),
),
CastError::NeedViaThinPtr => (
DiagnosticCode::RustcHardError("E0606"),
format_ty!(
ctx,
"casting `{}` as `{}` is invalid: needs casting through a thin pointer first",
d.expr_ty,
d.cast_ty
),
),
CastError::NeedViaInt => (
DiagnosticCode::RustcHardError("E0606"),
format_ty!(
ctx,
"casting `{}` as `{}` is invalid: needs casting through an integer first",
d.expr_ty,
d.cast_ty
),
),
CastError::NonScalar => (
DiagnosticCode::RustcHardError("E0605"),
format_ty!(ctx, "non-primitive cast: `{}` as `{}`", d.expr_ty, d.cast_ty),
),
};
Diagnostic::new(code, message, display_range)
}
pub(crate) fn cast_to_unsized(ctx: &DiagnosticsContext<'_>, d: &hir::CastToUnsized) -> Diagnostic {
let display_range = ctx.sema.diagnostics_display_range(d.expr.map(|it| it.into()));
Diagnostic::new(
DiagnosticCode::RustcHardError("E0620"),
format_ty!(ctx, "cast to unsized type: `{}`", d.cast_ty),
display_range,
)
}
#[cfg(test)]
mod tests {
use crate::tests::{check_diagnostics, check_diagnostics_with_disabled};
#[test]
fn cast_as_bool() {
check_diagnostics(
r#"
//- minicore: sized
fn main() {
let u = 5 as bool;
//^^^^^^^^^ error: cannot cast `i32` as `bool`
let t = (1 + 2) as bool;
//^^^^^^^^^^^^^^^ error: cannot cast `i32` as `bool`
let _ = 5_u32 as bool;
//^^^^^^^^^^^^^ error: cannot cast `u32` as `bool`
let _ = 64.0_f64 as bool;
//^^^^^^^^^^^^^^^^ error: cannot cast `f64` as `bool`
enum IntEnum {
Zero,
One,
Two
}
let _ = IntEnum::One as bool;
//^^^^^^^^^^^^^^^^^^^^ error: cannot cast `IntEnum` as `bool`
fn uwu(_: u8) -> i32 {
5
}
unsafe fn owo() {}
let _ = uwu as bool;
//^^^^^^^^^^^ error: cannot cast `fn uwu(u8) -> i32` as `bool`
let _ = owo as bool;
//^^^^^^^^^^^ error: cannot cast `unsafe fn owo()` as `bool`
let _ = uwu as fn(u8) -> i32 as bool;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: cannot cast `fn(u8) -> i32` as `bool`
let _ = 'x' as bool;
//^^^^^^^^^^^ error: cannot cast `char` as `bool`
let ptr = 1 as *const ();
let _ = ptr as bool;
//^^^^^^^^^^^ error: cannot cast `*const ()` as `bool`
let v = "hello" as bool;
//^^^^^^^^^^^^^^^ error: casting `&str` as `bool` is invalid: needs casting through a raw pointer first
}
"#,
);
}
#[test]
fn cast_pointee_projection() {
check_diagnostics(
r#"
//- minicore: sized
trait Tag<'a> {
type Type: ?Sized;
}
trait IntoRaw: for<'a> Tag<'a> {
fn into_raw(this: *const <Self as Tag<'_>>::Type) -> *mut <Self as Tag<'_>>::Type;
}
impl<T: for<'a> Tag<'a>> IntoRaw for T {
fn into_raw(this: *const <Self as Tag<'_>>::Type) -> *mut <Self as Tag<'_>>::Type {
this as *mut T::Type
}
}
fn main() {}
"#,
);
}
#[test]
fn cast_region_to_int() {
check_diagnostics(
r#"
//- minicore: sized
fn main() {
let x: isize = 3;
let _ = &x as *const isize as usize;
}
"#,
);
}
#[test]
fn cast_to_bare_fn() {
check_diagnostics(
r#"
//- minicore: sized
fn foo(_x: isize) { }
fn main() {
let v: u64 = 5;
let x = foo as extern "C" fn() -> isize;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `fn foo(isize)` as `fn() -> isize`
let y = v as extern "Rust" fn(isize) -> (isize, isize);
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `u64` as `fn(isize) -> (isize, isize)`
y(x());
}
"#,
);
}
#[test]
fn cast_to_unit() {
check_diagnostics(
r#"
//- minicore: sized
fn main() {
let _ = 0u32 as ();
//^^^^^^^^^^ error: non-primitive cast: `u32` as `()`
}
"#,
);
}
#[test]
fn cast_to_slice() {
check_diagnostics_with_disabled(
r#"
//- minicore: sized
fn as_bytes(_: &str) -> &[u8] {
loop {}
}
fn main() {
as_bytes("example") as [char];
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: cast to unsized type: `[char]`
let arr: &[u8] = &[0, 2, 3];
arr as [char];
//^^^^^^^^^^^^^ error: cast to unsized type: `[char]`
}
"#,
&["E0308"],
);
}
#[test]
fn cast() {
check_diagnostics(
r#"
//- minicore: sized
fn null_mut<T: ?Sized>() -> *mut T {
loop {}
}
pub fn main() {
let i: isize = 'Q' as isize;
let _u: u32 = i as u32;
// Test that `_` is correctly inferred.
let x = &"hello";
let mut y = x as *const _;
y = null_mut();
}
"#,
);
}
#[test]
fn dyn_tail_need_normalization() {
check_diagnostics(
r#"
//- minicore: dispatch_from_dyn
trait Trait {
type Associated;
}
impl Trait for i32 {
type Associated = i64;
}
trait Generic<T> {}
type TraitObject = dyn Generic<<i32 as Trait>::Associated>;
struct Wrap(TraitObject);
fn cast(x: *mut TraitObject) {
x as *mut Wrap;
}
"#,
);
}
#[test]
fn enum_to_numeric_cast() {
check_diagnostics(
r#"
//- minicore: sized
pub enum UnitOnly {
Foo,
Bar,
Baz,
}
pub enum Fieldless {
Tuple(),
Struct{},
Unit,
}
pub enum NotUnitOnlyOrFieldless {
Foo,
Bar(u8),
Baz
}
fn main() {
let unit_only = UnitOnly::Foo;
let _ = unit_only as isize;
let _ = unit_only as i32;
let _ = unit_only as usize;
let _ = unit_only as u32;
let fieldless = Fieldless::Struct{};
let _ = fieldless as isize;
let _ = fieldless as i32;
let _ = fieldless as usize;
let _ = fieldless as u32;
let not_unit_only_or_fieldless = NotUnitOnlyOrFieldless::Foo;
let _ = not_unit_only_or_fieldless as isize;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `NotUnitOnlyOrFieldless` as `isize`
let _ = not_unit_only_or_fieldless as i32;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `NotUnitOnlyOrFieldless` as `i32`
let _ = not_unit_only_or_fieldless as usize;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `NotUnitOnlyOrFieldless` as `usize`
let _ = not_unit_only_or_fieldless as u32;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `NotUnitOnlyOrFieldless` as `u32`
}
"#,
);
}
#[test]
fn fat_ptr_cast() {
check_diagnostics_with_disabled(
r#"
//- minicore: sized
trait Foo {
fn foo(&self) {} //~ WARN method `foo` is never used
}
struct Bar;
impl Foo for Bar {}
fn to_raw<T>(_: *mut T) -> *mut () {
loop {}
}
fn main() {
// Test we can turn a fat pointer to array back into a thin pointer.
let a: *const [i32] = &[1, 2, 3];
let b = a as *const [i32; 2];
// Test conversion to an address (usize).
let a: *const [i32; 3] = &[1, 2, 3];
let b: *const [i32] = a;
// And conversion to a void pointer/address for trait objects too.
let a: *mut dyn Foo = &mut Bar;
let b = a as *mut () as usize;
let c = a as *const () as usize;
let d = to_raw(a) as usize;
}
"#,
&["E0308"],
);
check_diagnostics_with_disabled(
r#"
//- minicore: sized
trait Trait {}
struct Box<T: ?Sized>;
impl<T: ?Sized> Box<T> {
fn new(_: T) -> Self {
loop {}
}
}
fn as_ptr(_: &[i32]) -> *const i32 {
loop {}
}
fn main() {
let a: &[i32] = &[1, 2, 3];
let b: Box<[i32]> = Box::new([1, 2, 3]);
let p = a as *const [i32];
let q = as_ptr(a);
a as usize;
//^^^^^^^^^^ error: casting `&[i32]` as `usize` is invalid: needs casting through a raw pointer first
a as isize;
//^^^^^^^^^^ error: casting `&[i32]` as `isize` is invalid: needs casting through a raw pointer first
a as i16;
//^^^^^^^^ error: casting `&[i32]` as `i16` is invalid: needs casting through a raw pointer first
a as u32;
//^^^^^^^^ error: casting `&[i32]` as `u32` is invalid: needs casting through a raw pointer first
b as usize;
//^^^^^^^^^^ error: non-primitive cast: `Box<[i32]>` as `usize`
p as usize;
//^^^^^^^^^^ error: casting `*const [i32]` as `usize` is invalid: needs casting through a thin pointer first
q as *const [i32];
//^^^^^^^^^^^^^^^^^ error: cannot cast thin pointer `*const i32` to fat pointer `*const [i32]`
let t: *mut (dyn Trait + 'static) = 0 as *mut _;
//^^^^^^^^^^^ error: cannot cast `usize` to a fat pointer `*mut _`
let mut fail: *const str = 0 as *const str;
//^^^^^^^^^^^^^^^ error: cannot cast `usize` to a fat pointer `*const str`
let mut fail2: *const str = 0isize as *const str;
//^^^^^^^^^^^^^^^^^^^^ error: cannot cast `isize` to a fat pointer `*const str`
}
fn foo<T: ?Sized>() {
let s = 0 as *const T;
//^^^^^^^^^^^^^ error: cannot cast `usize` to a fat pointer `*const T`
}
"#,
&["E0308", "unused_variables"],
);
}
#[test]
fn ptr_to_ptr_different_regions() {
check_diagnostics(
r#"
//- minicore: sized
struct Foo<'a> { a: &'a () }
fn extend_lifetime_very_very_safely<'a>(v: *const Foo<'a>) -> *const Foo<'static> {
// This should pass because raw pointer casts can do anything they want.
v as *const Foo<'static>
}
trait Trait {}
fn assert_static<'a>(ptr: *mut (dyn Trait + 'a)) -> *mut (dyn Trait + 'static) {
ptr as _
}
fn main() {
let unit = ();
let foo = Foo { a: &unit };
let _long: *const Foo<'static> = extend_lifetime_very_very_safely(&foo);
}
"#,
);
}
#[test]
fn ptr_to_trait_obj_add_auto() {
check_diagnostics(
r#"
//- minicore: pointee
trait Trait<'a> {}
fn add_auto<'a>(x: *mut dyn Trait<'a>) -> *mut (dyn Trait<'a> + Send) {
x as _
}
// (to test diagnostic list formatting)
fn add_multiple_auto<'a>(x: *mut dyn Trait<'a>) -> *mut (dyn Trait<'a> + Send + Sync + Unpin) {
x as _
}
"#,
);
}
#[test]
fn ptr_to_trait_obj_add_super_auto() {
check_diagnostics(
r#"
//- minicore: pointee
trait Trait: Send {}
impl Trait for () {}
fn main() {
// This is OK: `Trait` has `Send` super trait.
&() as *const dyn Trait as *const (dyn Trait + Send);
}
"#,
);
}
#[test]
fn ptr_to_trait_obj_ok() {
check_diagnostics(
r#"
//- minicore: pointee
trait Trait<'a> {}
fn remove_auto<'a>(x: *mut (dyn Trait<'a> + Send)) -> *mut dyn Trait<'a> {
x as _
}
fn cast_inherent_lt<'a, 'b>(x: *mut (dyn Trait<'static> + 'a)) -> *mut (dyn Trait<'static> + 'b) {
x as _
}
fn unprincipled<'a, 'b>(x: *mut (dyn Send + 'a)) -> *mut (dyn Sync + 'b) {
x as _
}
"#,
);
}
#[ignore = "issue #18047"]
#[test]
fn ptr_to_trait_obj_wrap_upcast() {
check_diagnostics(
r#"
//- minicore: sized
trait Super {}
trait Sub: Super {}
struct Wrapper<T: ?Sized>(T);
// This cast should not compile.
// Upcasting can't work here, because we are also changing the type (`Wrapper`),
// and reinterpreting would be confusing/surprising.
// See <https://github.com/rust-lang/rust/pull/120248#discussion_r1487739518>
fn cast(ptr: *const dyn Sub) -> *const Wrapper<dyn Super> {
ptr as _
//^^^^^^^^ error: casting `*const dyn Sub` as `*const Wrapper<dyn Super>` is invalid: vtable kinds may not match
}
"#,
);
}
#[test]
fn supported_cast() {
check_diagnostics(
r#"
//- minicore: sized
pub fn main() {
struct String;
let f = 1_usize as *const String;
let _ = f as isize;
let _ = f as usize;
let _ = f as i8;
let _ = f as i16;
let _ = f as i32;
let _ = f as i64;
let _ = f as u8;
let _ = f as u16;
let _ = f as u32;
let _ = f as u64;
let _ = 1 as isize;
let _ = 1 as usize;
let _ = 1 as *const String;
let _ = 1 as i8;
let _ = 1 as i16;
let _ = 1 as i32;
let _ = 1 as i64;
let _ = 1 as u8;
let _ = 1 as u16;
let _ = 1 as u32;
let _ = 1 as u64;
let _ = 1 as f32;
let _ = 1 as f64;
let _ = 1_usize as isize;
let _ = 1_usize as usize;
let _ = 1_usize as *const String;
let _ = 1_usize as i8;
let _ = 1_usize as i16;
let _ = 1_usize as i32;
let _ = 1_usize as i64;
let _ = 1_usize as u8;
let _ = 1_usize as u16;
let _ = 1_usize as u32;
let _ = 1_usize as u64;
let _ = 1_usize as f32;
let _ = 1_usize as f64;
let _ = 1i8 as isize;
let _ = 1i8 as usize;
let _ = 1i8 as *const String;
let _ = 1i8 as i8;
let _ = 1i8 as i16;
let _ = 1i8 as i32;
let _ = 1i8 as i64;
let _ = 1i8 as u8;
let _ = 1i8 as u16;
let _ = 1i8 as u32;
let _ = 1i8 as u64;
let _ = 1i8 as f32;
let _ = 1i8 as f64;
let _ = 1u8 as isize;
let _ = 1u8 as usize;
let _ = 1u8 as *const String;
let _ = 1u8 as i8;
let _ = 1u8 as i16;
let _ = 1u8 as i32;
let _ = 1u8 as i64;
let _ = 1u8 as u8;
let _ = 1u8 as u16;
let _ = 1u8 as u32;
let _ = 1u8 as u64;
let _ = 1u8 as f32;
let _ = 1u8 as f64;
let _ = 1i16 as isize;
let _ = 1i16 as usize;
let _ = 1i16 as *const String;
let _ = 1i16 as i8;
let _ = 1i16 as i16;
let _ = 1i16 as i32;
let _ = 1i16 as i64;
let _ = 1i16 as u8;
let _ = 1i16 as u16;
let _ = 1i16 as u32;
let _ = 1i16 as u64;
let _ = 1i16 as f32;
let _ = 1i16 as f64;
let _ = 1u16 as isize;
let _ = 1u16 as usize;
let _ = 1u16 as *const String;
let _ = 1u16 as i8;
let _ = 1u16 as i16;
let _ = 1u16 as i32;
let _ = 1u16 as i64;
let _ = 1u16 as u8;
let _ = 1u16 as u16;
let _ = 1u16 as u32;
let _ = 1u16 as u64;
let _ = 1u16 as f32;
let _ = 1u16 as f64;
let _ = 1i32 as isize;
let _ = 1i32 as usize;
let _ = 1i32 as *const String;
let _ = 1i32 as i8;
let _ = 1i32 as i16;
let _ = 1i32 as i32;
let _ = 1i32 as i64;
let _ = 1i32 as u8;
let _ = 1i32 as u16;
let _ = 1i32 as u32;
let _ = 1i32 as u64;
let _ = 1i32 as f32;
let _ = 1i32 as f64;
let _ = 1u32 as isize;
let _ = 1u32 as usize;
let _ = 1u32 as *const String;
let _ = 1u32 as i8;
let _ = 1u32 as i16;
let _ = 1u32 as i32;
let _ = 1u32 as i64;
let _ = 1u32 as u8;
let _ = 1u32 as u16;
let _ = 1u32 as u32;
let _ = 1u32 as u64;
let _ = 1u32 as f32;
let _ = 1u32 as f64;
let _ = 1i64 as isize;
let _ = 1i64 as usize;
let _ = 1i64 as *const String;
let _ = 1i64 as i8;
let _ = 1i64 as i16;
let _ = 1i64 as i32;
let _ = 1i64 as i64;
let _ = 1i64 as u8;
let _ = 1i64 as u16;
let _ = 1i64 as u32;
let _ = 1i64 as u64;
let _ = 1i64 as f32;
let _ = 1i64 as f64;
let _ = 1u64 as isize;
let _ = 1u64 as usize;
let _ = 1u64 as *const String;
let _ = 1u64 as i8;
let _ = 1u64 as i16;
let _ = 1u64 as i32;
let _ = 1u64 as i64;
let _ = 1u64 as u8;
let _ = 1u64 as u16;
let _ = 1u64 as u32;
let _ = 1u64 as u64;
let _ = 1u64 as f32;
let _ = 1u64 as f64;
let _ = 1u64 as isize;
let _ = 1u64 as usize;
let _ = 1u64 as *const String;
let _ = 1u64 as i8;
let _ = 1u64 as i16;
let _ = 1u64 as i32;
let _ = 1u64 as i64;
let _ = 1u64 as u8;
let _ = 1u64 as u16;
let _ = 1u64 as u32;
let _ = 1u64 as u64;
let _ = 1u64 as f32;
let _ = 1u64 as f64;
let _ = true as isize;
let _ = true as usize;
let _ = true as i8;
let _ = true as i16;
let _ = true as i32;
let _ = true as i64;
let _ = true as u8;
let _ = true as u16;
let _ = true as u32;
let _ = true as u64;
let _ = 1f32 as isize;
let _ = 1f32 as usize;
let _ = 1f32 as i8;
let _ = 1f32 as i16;
let _ = 1f32 as i32;
let _ = 1f32 as i64;
let _ = 1f32 as u8;
let _ = 1f32 as u16;
let _ = 1f32 as u32;
let _ = 1f32 as u64;
let _ = 1f32 as f32;
let _ = 1f32 as f64;
let _ = 1f64 as isize;
let _ = 1f64 as usize;
let _ = 1f64 as i8;
let _ = 1f64 as i16;
let _ = 1f64 as i32;
let _ = 1f64 as i64;
let _ = 1f64 as u8;
let _ = 1f64 as u16;
let _ = 1f64 as u32;
let _ = 1f64 as u64;
let _ = 1f64 as f32;
let _ = 1f64 as f64;
}
"#,
);
}
#[test]
fn unsized_struct_cast() {
check_diagnostics(
r#"
//- minicore: sized
pub struct Data([u8]);
fn foo(x: &[u8]) {
let _: *const Data = x as *const Data;
//^^^^^^^^^^^^^^^^ error: casting `&[u8]` as `*const Data` is invalid
}
"#,
);
}
#[test]
fn unsupported_cast() {
check_diagnostics(
r#"
//- minicore: sized
struct A;
fn main() {
let _ = 1.0 as *const A;
//^^^^^^^^^^^^^^^ error: casting `f64` as `*const A` is invalid
}
"#,
);
}
#[test]
fn issue_17897() {
check_diagnostics(
r#"
//- minicore: sized
fn main() {
_ = ((), ()) as ();
//^^^^^^^^^^^^^^ error: non-primitive cast: `((), ())` as `()`
}
"#,
);
}
#[test]
fn rustc_issue_10991() {
check_diagnostics(
r#"
//- minicore: sized
fn main() {
let nil = ();
let _t = nil as usize;
//^^^^^^^^^^^^ error: non-primitive cast: `()` as `usize`
}
"#,
);
}
#[test]
fn rustc_issue_17444() {
check_diagnostics(
r#"
//- minicore: sized
enum Test {
Foo = 0
}
fn main() {
let _x = Test::Foo as *const isize;
//^^^^^^^^^^^^^^^^^^^^^^^^^ error: casting `Test` as `*const isize` is invalid
}
"#,
);
}
#[test]
fn rustc_issue_43825() {
check_diagnostics(
r#"
//- minicore: sized
fn main() {
let error = error;
//^^^^^ error: no such value in this scope
0 as f32;
0.0 as u32;
}
"#,
);
}
#[test]
fn rustc_issue_84213() {
check_diagnostics(
r#"
//- minicore: sized
struct Something {
pub field: u32,
}
fn main() {
let mut something = Something { field: 1337 };
let _ = something.field;
let _pointer_to_something = something as *const Something;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `Something` as `*const Something`
let _mut_pointer_to_something = something as *mut Something;
//^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `Something` as `*mut Something`
}
"#,
);
check_diagnostics(
r#"
//- minicore: sized
struct Something {
pub field: u32,
}
fn main() {
let mut something = Something { field: 1337 };
let _ = something.field;
let _pointer_to_something = &something as *const Something;
let _mut_pointer_to_something = &mut something as *mut Something;
}
"#,
);
}
#[test]
fn rustc_issue_88621() {
check_diagnostics(
r#"
//- minicore: sized
#[repr(u8)]
enum Kind2 {
Foo() = 1,
Bar{} = 2,
Baz = 3,
}
fn main() {
let _ = Kind2::Foo() as u8;
//^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `Kind2` as `u8`
}
"#,
);
}
#[test]
fn rustc_issue_89497() {
check_diagnostics(
r#"
//- minicore: sized
fn main() {
let pointer: usize = &1_i32 as *const i32 as usize;
let _reference: &'static i32 = unsafe { pointer as *const i32 as &'static i32 };
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: non-primitive cast: `*const i32` as `&i32`
}
"#,
);
check_diagnostics(
r#"
//- minicore: sized
fn main() {
let pointer: usize = &1_i32 as *const i32 as usize;
let _reference: &'static i32 = unsafe { &*(pointer as *const i32) };
}
"#,
);
}
#[test]
fn rustc_issue_106883() {
check_diagnostics_with_disabled(
r#"
//- minicore: sized, deref
use core::ops::Deref;
struct Foo;
impl Deref for Foo {
type Target = [u8];
fn deref(&self) -> &Self::Target {
&[]
}
}
fn main() {
let _ = "foo" as bool;
//^^^^^^^^^^^^^ error: casting `&str` as `bool` is invalid: needs casting through a raw pointer first
let _ = Foo as bool;
//^^^^^^^^^^^ error: non-primitive cast: `Foo` as `bool`
}
fn _slice(bar: &[i32]) -> bool {
bar as bool
//^^^^^^^^^^^ error: casting `&[i32]` as `bool` is invalid: needs casting through a raw pointer first
}
"#,
&["E0308"],
);
}
#[test]
fn trait_upcasting() {
check_diagnostics(
r#"
//- minicore: coerce_unsized, dispatch_from_dyn
#![feature(trait_upcasting)]
trait Foo {}
trait Bar: Foo {}
impl dyn Bar {
fn bar(&self) {
_ = self as &dyn Foo;
}
}
"#,
);
}
#[test]
fn issue_18047() {
check_diagnostics(
r#"
//- minicore: coerce_unsized, dispatch_from_dyn
trait LocalFrom<T> {
fn from(_: T) -> Self;
}
trait LocalInto<T> {
fn into(self) -> T;
}
impl<T, U> LocalInto<U> for T
where
U: LocalFrom<T>,
{
fn into(self) -> U {
U::from(self)
}
}
impl<T> LocalFrom<T> for T {
fn from(t: T) -> T {
t
}
}
trait Foo {
type ErrorType;
type Assoc;
}
trait Bar {
type ErrorType;
}
struct ErrorLike;
impl<E> LocalFrom<E> for ErrorLike
where
E: Trait + 'static,
{
fn from(_: E) -> Self {
loop {}
}
}
trait Baz {
type Assoc: Bar;
type Error: LocalInto<ErrorLike>;
}
impl<T, U> Baz for T
where
T: Foo<Assoc = U>,
T::ErrorType: LocalInto<ErrorLike>,
U: Bar,
<U as Bar>::ErrorType: LocalInto<ErrorLike>,
{
type Assoc = U;
type Error = T::ErrorType;
}
struct S;
trait Trait {}
impl Trait for S {}
fn test<T>()
where
T: Baz,
T::Assoc: 'static,
{
let _ = &S as &dyn Trait;
}
"#,
);
}
#[test]
fn cast_literal_to_char() {
check_diagnostics(
r#"
fn foo() {
0 as char;
}
"#,
);
}
#[test]
fn cast_isize_to_infer_pointer() {
check_diagnostics(
r#"
//- minicore: coerce_unsized
struct Foo {}
struct Wrap<'a>(&'a mut Foo);
fn main() {
let lparam: isize = 0;
let _wrap = Wrap(unsafe { &mut *(lparam as *mut _) });
}
"#,
);
}
}