36 lines
893 B
Rust
36 lines
893 B
Rust
use std::mem;
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fn eq_ref<T>(x: &T, y: &T) -> bool {
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x as *const _ == y as *const _
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}
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fn f() -> i32 { 42 }
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fn main() {
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// int-ptr-int
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assert_eq!(1 as *const i32 as usize, 1);
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assert_eq!((1 as *const i32).wrapping_offset(4) as usize, 1 + 4*4);
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{ // ptr-int-ptr
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let x = 13;
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let mut y = &x as &_ as *const _ as usize;
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y += 13;
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y -= 13;
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let y = y as *const _;
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assert!(eq_ref(&x, unsafe { &*y }));
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}
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{ // fnptr-int-fnptr
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let x : fn() -> i32 = f;
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let y : *mut u8 = unsafe { mem::transmute(x as fn() -> i32) };
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let mut y = y as usize;
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y += 13;
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y -= 13;
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let x : fn() -> i32 = unsafe { mem::transmute(y as *mut u8) };
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assert_eq!(x(), 42);
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}
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// involving types other than usize
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assert_eq!((-1i32) as usize as *const i32 as usize, (-1i32) as usize);
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}
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