src/test/compile-fail/cast-rfc0401.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 fn illegal_cast<U:?Sized,V:?Sized>(u: *const U) -> *const V
  12 {
  13     u as *const V
  14     //~^ ERROR casting
  15     //~^^ NOTE vtable kinds
  16 }
  17
  18 fn illegal_cast_2<U:?Sized>(u: *const U) -> *const str
  19 {
  20     u as *const str
  21     //~^ ERROR casting
  22     //~^^ NOTE vtable kinds
  23 }
  24
  25 trait Foo { fn foo(&self) {} }
  26 impl<T> Foo for T {}
  27
  28 trait Bar { fn foo(&self) {} }
  29 impl<T> Bar for T {}
  30
  31 enum E {
  32     A, B
  33 }
  34
  35 fn main()
  36 {
  37     let f: f32 = 1.2;
  38     let v = 0 as *const u8;
  39     let fat_v : *const [u8] = unsafe { &*(0 as *const [u8; 1])};
  40     let fat_sv : *const [i8] = unsafe { &*(0 as *const [i8; 1])};
  41     let foo: &Foo = &f;
  42
  43     let _ = v as &u8; //~ ERROR non-scalar
  44     let _ = v as E; //~ ERROR non-scalar
  45     let _ = v as fn(); //~ ERROR non-scalar
  46     let _ = v as (u32,); //~ ERROR non-scalar
  47     let _ = Some(&v) as *const u8; //~ ERROR non-scalar
  48
  49     let _ = v as f32;
  50     //~^ ERROR casting
  51     //~^^ HELP through a usize first
  52     let _ = main as f64;
  53     //~^ ERROR casting
  54     //~^^ HELP through a usize first
  55     let _ = &v as usize;
  56     //~^ ERROR casting
  57     //~^^ HELP through a raw pointer first
  58     let _ = f as *const u8;
  59     //~^ ERROR casting
  60     //~^^ HELP through a usize first
  61     let _ = 3 as bool;
  62     //~^ ERROR cannot cast as `bool`
  63     //~^^ HELP compare with zero
  64     //~^^^ HELP run `rustc --explain E0054` to see a detailed explanation
  65     let _ = E::A as bool;
  66     //~^ ERROR cannot cast as `bool`
  67     //~^^ HELP compare with zero
  68     //~^^^ HELP run `rustc --explain E0054` to see a detailed explanation
  69     let _ = 0x61u32 as char; //~ ERROR only `u8` can be cast
  70
  71     let _ = false as f32;
  72     //~^ ERROR casting
  73     //~^^ HELP through an integer first
  74     let _ = E::A as f32;
  75     //~^ ERROR casting
  76     //~^^ HELP through an integer first
  77     let _ = 'a' as f32;
  78     //~^ ERROR casting
  79     //~^^ HELP through an integer first
  80
  81     let _ = false as *const u8;
  82     //~^ ERROR casting
  83     //~^^ HELP through a usize first
  84     let _ = E::A as *const u8;
  85     //~^ ERROR casting
  86     //~^^ HELP through a usize first
  87     let _ = 'a' as *const u8;
  88     //~^ ERROR casting
  89     //~^^ HELP through a usize first
  90
  91     let _ = 42usize as *const [u8]; //~ ERROR casting
  92     let _ = v as *const [u8]; //~ ERROR cannot cast
  93     let _ = fat_v as *const Foo;
  94     //~^ ERROR the trait bound `[u8]: std::marker::Sized` is not satisfied
  95     //~^^ HELP run `rustc --explain E0277` to see a detailed explanation
  96     //~^^^ NOTE `[u8]` does not have a constant size known at compile-time
  97     //~^^^^ NOTE required for the cast to the object type `Foo`
  98     let _ = foo as *const str; //~ ERROR casting
  99     let _ = foo as *mut str; //~ ERROR casting
 100     let _ = main as *mut str; //~ ERROR casting
 101     let _ = &f as *mut f32; //~ ERROR casting
 102     let _ = &f as *const f64; //~ ERROR casting
 103     let _ = fat_sv as usize;
 104     //~^ ERROR casting
 105     //~^^ HELP through a thin pointer first
 106
 107     let a : *const str = "hello";
 108     let _ = a as *const Foo;
 109     //~^ ERROR the trait bound `str: std::marker::Sized` is not satisfied
 110     //~^^ HELP run `rustc --explain E0277` to see a detailed explanation
 111     //~^^^ NOTE `str` does not have a constant size known at compile-time
 112     //~^^^^ NOTE required for the cast to the object type `Foo`
 113
 114     // check no error cascade
 115     let _ = main.f as *const u32; //~ ERROR attempted access of field
 116
 117     let cf: *const Foo = &0;
 118     let _ = cf as *const [u16];
 119     //~^ ERROR casting
 120     //~^^ NOTE vtable kinds
 121     let _ = cf as *const Bar;
 122     //~^ ERROR casting
 123     //~^^ NOTE vtable kinds
 124 }