fn report_cast_error(&self, fcx: &FnCtxt<'a, 'gcx, 'tcx>, e: CastError) {
match e {
CastError::NeedDeref => {
+ let error_span = self.span;
let cast_ty = fcx.ty_to_string(self.cast_ty);
- let mut err = fcx.type_error_struct(self.cast_span,
+ let mut err = fcx.type_error_struct(error_span,
|actual| {
format!("casting `{}` as `{}` is invalid",
actual,
cast_ty)
},
self.expr_ty);
- err.span_label(self.expr.span,
+ err.span_label(error_span,
&format!("cannot cast `{}` as `{}`",
fcx.ty_to_string(self.expr_ty),
cast_ty));
if let Ok(snippet) = fcx.sess().codemap().span_to_snippet(self.expr.span) {
- err.span_label(self.expr.span,
+ err.span_help(self.expr.span,
&format!("did you mean `*{}`?", snippet));
}
err.emit();
+++ /dev/null
-// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-fn illegal_cast<U:?Sized,V:?Sized>(u: *const U) -> *const V
-{
- u as *const V
- //~^ ERROR casting
- //~^^ NOTE vtable kinds
-}
-
-fn illegal_cast_2<U:?Sized>(u: *const U) -> *const str
-{
- u as *const str
- //~^ ERROR casting
- //~^^ NOTE vtable kinds
-}
-
-trait Foo { fn foo(&self) {} }
-impl<T> Foo for T {}
-
-trait Bar { fn foo(&self) {} }
-impl<T> Bar for T {}
-
-enum E {
- A, B
-}
-
-fn main()
-{
- let f: f32 = 1.2;
- let v = 0 as *const u8;
- let fat_v : *const [u8] = unsafe { &*(0 as *const [u8; 1])};
- let fat_sv : *const [i8] = unsafe { &*(0 as *const [i8; 1])};
- let foo: &Foo = &f;
-
- let _ = v as &u8; //~ ERROR non-scalar
- let _ = v as E; //~ ERROR non-scalar
- let _ = v as fn(); //~ ERROR non-scalar
- let _ = v as (u32,); //~ ERROR non-scalar
- let _ = Some(&v) as *const u8; //~ ERROR non-scalar
-
- let _ = v as f32;
- //~^ ERROR casting
- let _ = main as f64;
- //~^ ERROR casting
- let _ = &v as usize;
- //~^ ERROR casting
- //~^^ HELP through a raw pointer first
- let _ = f as *const u8;
- //~^ ERROR casting
- let _ = 3_i32 as bool;
- //~^ ERROR cannot cast as `bool` [E0054]
- //~| unsupported cast
- //~| HELP compare with zero
- let _ = E::A as bool;
- //~^ ERROR cannot cast as `bool` [E0054]
- //~| unsupported cast
- //~| HELP compare with zero
- let _ = 0x61u32 as char; //~ ERROR only `u8` can be cast
-
- let _ = false as f32;
- //~^ ERROR casting
- //~^^ HELP through an integer first
- let _ = E::A as f32;
- //~^ ERROR casting
- //~^^ HELP through an integer first
- let _ = 'a' as f32;
- //~^ ERROR casting
- //~^^ HELP through an integer first
-
- let _ = false as *const u8;
- //~^ ERROR casting
- let _ = E::A as *const u8;
- //~^ ERROR casting
- let _ = 'a' as *const u8;
- //~^ ERROR casting
-
- let _ = 42usize as *const [u8]; //~ ERROR casting
- let _ = v as *const [u8]; //~ ERROR cannot cast
- let _ = fat_v as *const Foo;
- //~^ ERROR the trait bound `[u8]: std::marker::Sized` is not satisfied
- //~| NOTE the trait `std::marker::Sized` is not implemented for `[u8]`
- //~| NOTE `[u8]` does not have a constant size known at compile-time
- //~| NOTE required for the cast to the object type `Foo`
- let _ = foo as *const str; //~ ERROR casting
- let _ = foo as *mut str; //~ ERROR casting
- let _ = main as *mut str; //~ ERROR casting
- let _ = &f as *mut f32; //~ ERROR casting
- let _ = &f as *const f64; //~ ERROR casting
- let _ = fat_sv as usize;
- //~^ ERROR casting
- //~^^ HELP through a thin pointer first
-
- let a : *const str = "hello";
- let _ = a as *const Foo;
- //~^ ERROR the trait bound `str: std::marker::Sized` is not satisfied
- //~| NOTE the trait `std::marker::Sized` is not implemented for `str`
- //~| NOTE `str` does not have a constant size known at compile-time
- //~| NOTE required for the cast to the object type `Foo`
-
- // check no error cascade
- let _ = main.f as *const u32; //~ no field `f` on type `fn() {main}`
-
- let cf: *const Foo = &0;
- let _ = cf as *const [u16];
- //~^ ERROR casting
- //~^^ NOTE vtable kinds
- let _ = cf as *const Bar;
- //~^ ERROR casting
- //~^^ NOTE vtable kinds
-
- vec![0.0].iter().map(|s| s as f32).collect::<Vec<f32>>();
- //~^ ERROR casting `&{float}` as `f32` is invalid
- //~| NOTE cannot cast `&{float}` as `f32`
- //~| NOTE did you mean `*s`?
-}
--- /dev/null
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn illegal_cast<U:?Sized,V:?Sized>(u: *const U) -> *const V
+{
+ u as *const V
+}
+
+fn illegal_cast_2<U:?Sized>(u: *const U) -> *const str
+{
+ u as *const str
+}
+
+trait Foo { fn foo(&self) {} }
+impl<T> Foo for T {}
+
+trait Bar { fn foo(&self) {} }
+impl<T> Bar for T {}
+
+enum E {
+ A, B
+}
+
+fn main()
+{
+ let f: f32 = 1.2;
+ let v = 0 as *const u8;
+ let fat_v : *const [u8] = unsafe { &*(0 as *const [u8; 1])};
+ let fat_sv : *const [i8] = unsafe { &*(0 as *const [i8; 1])};
+ let foo: &Foo = &f;
+
+ let _ = v as &u8;
+ let _ = v as E;
+ let _ = v as fn();
+ let _ = v as (u32,);
+ let _ = Some(&v) as *const u8;
+
+ let _ = v as f32;
+ let _ = main as f64;
+ let _ = &v as usize;
+ let _ = f as *const u8;
+ let _ = 3_i32 as bool;
+ let _ = E::A as bool;
+ let _ = 0x61u32 as char;
+
+ let _ = false as f32;
+ let _ = E::A as f32;
+ let _ = 'a' as f32;
+
+ let _ = false as *const u8;
+ let _ = E::A as *const u8;
+ let _ = 'a' as *const u8;
+
+ let _ = 42usize as *const [u8];
+ let _ = v as *const [u8];
+ let _ = fat_v as *const Foo;
+ let _ = foo as *const str;
+ let _ = foo as *mut str;
+ let _ = main as *mut str;
+ let _ = &f as *mut f32;
+ let _ = &f as *const f64;
+ let _ = fat_sv as usize;
+
+ let a : *const str = "hello";
+ let _ = a as *const Foo;
+
+ // check no error cascade
+ let _ = main.f as *const u32;
+
+ let cf: *const Foo = &0;
+ let _ = cf as *const [u16];
+ let _ = cf as *const Bar;
+
+ vec![0.0].iter().map(|s| s as f32).collect::<Vec<f32>>();
+}
--- /dev/null
+error: casting `*const U` as `*const V` is invalid
+ --> $DIR/cast-rfc0401.rs:13:5
+ |
+13 | u as *const V
+ | ^^^^^^^^^^^^^
+ |
+ = note: vtable kinds may not match
+
+error: casting `*const U` as `*const str` is invalid
+ --> $DIR/cast-rfc0401.rs:18:5
+ |
+18 | u as *const str
+ | ^^^^^^^^^^^^^^^
+ |
+ = note: vtable kinds may not match
+
+error: no field `f` on type `fn() {main}`
+ --> $DIR/cast-rfc0401.rs:75:18
+ |
+75 | let _ = main.f as *const u32;
+ | ^
+
+error: non-scalar cast: `*const u8` as `&u8`
+ --> $DIR/cast-rfc0401.rs:39:13
+ |
+39 | let _ = v as &u8;
+ | ^^^^^^^^
+
+error: non-scalar cast: `*const u8` as `E`
+ --> $DIR/cast-rfc0401.rs:40:13
+ |
+40 | let _ = v as E;
+ | ^^^^^^
+
+error: non-scalar cast: `*const u8` as `fn()`
+ --> $DIR/cast-rfc0401.rs:41:13
+ |
+41 | let _ = v as fn();
+ | ^^^^^^^^^
+
+error: non-scalar cast: `*const u8` as `(u32,)`
+ --> $DIR/cast-rfc0401.rs:42:13
+ |
+42 | let _ = v as (u32,);
+ | ^^^^^^^^^^^
+
+error: non-scalar cast: `std::option::Option<&*const u8>` as `*const u8`
+ --> $DIR/cast-rfc0401.rs:43:13
+ |
+43 | let _ = Some(&v) as *const u8;
+ | ^^^^^^^^^^^^^^^^^^^^^
+
+error: casting `*const u8` as `f32` is invalid
+ --> $DIR/cast-rfc0401.rs:45:13
+ |
+45 | let _ = v as f32;
+ | ^^^^^^^^
+
+error: casting `fn() {main}` as `f64` is invalid
+ --> $DIR/cast-rfc0401.rs:46:13
+ |
+46 | let _ = main as f64;
+ | ^^^^^^^^^^^
+
+error: casting `&*const u8` as `usize` is invalid
+ --> $DIR/cast-rfc0401.rs:47:13
+ |
+47 | let _ = &v as usize;
+ | ^^^^^^^^^^^
+ |
+ = help: cast through a raw pointer first
+
+error: casting `f32` as `*const u8` is invalid
+ --> $DIR/cast-rfc0401.rs:48:13
+ |
+48 | let _ = f as *const u8;
+ | ^^^^^^^^^^^^^^
+
+error[E0054]: cannot cast as `bool`
+ --> $DIR/cast-rfc0401.rs:49:13
+ |
+49 | let _ = 3_i32 as bool;
+ | ^^^^^^^^^^^^^ unsupported cast
+ |
+ = help: compare with zero instead
+
+error[E0054]: cannot cast as `bool`
+ --> $DIR/cast-rfc0401.rs:50:13
+ |
+50 | let _ = E::A as bool;
+ | ^^^^^^^^^^^^ unsupported cast
+ |
+ = help: compare with zero instead
+
+error: only `u8` can be cast as `char`, not `u32`
+ --> $DIR/cast-rfc0401.rs:51:13
+ |
+51 | let _ = 0x61u32 as char;
+ | ^^^^^^^^^^^^^^^
+
+error: casting `bool` as `f32` is invalid
+ --> $DIR/cast-rfc0401.rs:53:13
+ |
+53 | let _ = false as f32;
+ | ^^^^^^^^^^^^
+ |
+ = help: cast through an integer first
+
+error: casting `E` as `f32` is invalid
+ --> $DIR/cast-rfc0401.rs:54:13
+ |
+54 | let _ = E::A as f32;
+ | ^^^^^^^^^^^
+ |
+ = help: cast through an integer first
+
+error: casting `char` as `f32` is invalid
+ --> $DIR/cast-rfc0401.rs:55:13
+ |
+55 | let _ = 'a' as f32;
+ | ^^^^^^^^^^
+ |
+ = help: cast through an integer first
+
+error: casting `bool` as `*const u8` is invalid
+ --> $DIR/cast-rfc0401.rs:57:13
+ |
+57 | let _ = false as *const u8;
+ | ^^^^^^^^^^^^^^^^^^
+
+error: casting `E` as `*const u8` is invalid
+ --> $DIR/cast-rfc0401.rs:58:13
+ |
+58 | let _ = E::A as *const u8;
+ | ^^^^^^^^^^^^^^^^^
+
+error: casting `char` as `*const u8` is invalid
+ --> $DIR/cast-rfc0401.rs:59:13
+ |
+59 | let _ = 'a' as *const u8;
+ | ^^^^^^^^^^^^^^^^
+
+error: casting `usize` as `*const [u8]` is invalid
+ --> $DIR/cast-rfc0401.rs:61:13
+ |
+61 | let _ = 42usize as *const [u8];
+ | ^^^^^^^^^^^^^^^^^^^^^^
+
+error: cannot cast thin pointer `*const u8` to fat pointer `*const [u8]`
+ --> $DIR/cast-rfc0401.rs:62:13
+ |
+62 | let _ = v as *const [u8];
+ | ^^^^^^^^^^^^^^^^
+
+error: casting `&Foo` as `*const str` is invalid
+ --> $DIR/cast-rfc0401.rs:64:13
+ |
+64 | let _ = foo as *const str;
+ | ^^^^^^^^^^^^^^^^^
+
+error: casting `&Foo` as `*mut str` is invalid
+ --> $DIR/cast-rfc0401.rs:65:13
+ |
+65 | let _ = foo as *mut str;
+ | ^^^^^^^^^^^^^^^
+
+error: casting `fn() {main}` as `*mut str` is invalid
+ --> $DIR/cast-rfc0401.rs:66:13
+ |
+66 | let _ = main as *mut str;
+ | ^^^^^^^^^^^^^^^^
+
+error: casting `&f32` as `*mut f32` is invalid
+ --> $DIR/cast-rfc0401.rs:67:13
+ |
+67 | let _ = &f as *mut f32;
+ | ^^^^^^^^^^^^^^
+
+error: casting `&f32` as `*const f64` is invalid
+ --> $DIR/cast-rfc0401.rs:68:13
+ |
+68 | let _ = &f as *const f64;
+ | ^^^^^^^^^^^^^^^^
+
+error: casting `*const [i8]` as `usize` is invalid
+ --> $DIR/cast-rfc0401.rs:69:13
+ |
+69 | let _ = fat_sv as usize;
+ | ^^^^^^^^^^^^^^^
+ |
+ = help: cast through a thin pointer first
+
+error: casting `*const Foo` as `*const [u16]` is invalid
+ --> $DIR/cast-rfc0401.rs:78:13
+ |
+78 | let _ = cf as *const [u16];
+ | ^^^^^^^^^^^^^^^^^^
+ |
+ = note: vtable kinds may not match
+
+error: casting `*const Foo` as `*const Bar` is invalid
+ --> $DIR/cast-rfc0401.rs:79:13
+ |
+79 | let _ = cf as *const Bar;
+ | ^^^^^^^^^^^^^^^^
+ |
+ = note: vtable kinds may not match
+
+error[E0277]: the trait bound `[u8]: std::marker::Sized` is not satisfied
+ --> $DIR/cast-rfc0401.rs:63:13
+ |
+63 | let _ = fat_v as *const Foo;
+ | ^^^^^ the trait `std::marker::Sized` is not implemented for `[u8]`
+ |
+ = note: `[u8]` does not have a constant size known at compile-time
+ = note: required for the cast to the object type `Foo`
+
+error[E0277]: the trait bound `str: std::marker::Sized` is not satisfied
+ --> $DIR/cast-rfc0401.rs:72:13
+ |
+72 | let _ = a as *const Foo;
+ | ^ the trait `std::marker::Sized` is not implemented for `str`
+ |
+ = note: `str` does not have a constant size known at compile-time
+ = note: required for the cast to the object type `Foo`
+
+error: casting `&{float}` as `f32` is invalid
+ --> $DIR/cast-rfc0401.rs:81:30
+ |
+81 | vec![0.0].iter().map(|s| s as f32).collect::<Vec<f32>>();
+ | ^^^^^^^^ cannot cast `&{float}` as `f32`
+ |
+help: did you mean `*s`?
+ --> $DIR/cast-rfc0401.rs:81:30
+ |
+81 | vec![0.0].iter().map(|s| s as f32).collect::<Vec<f32>>();
+ | ^
+
+error: aborting due to 34 previous errors
+
projects / rust.git / commitdiff