fixup and cool example for checked-uninit

pull/10/head
Alexis Beingessner 9 years ago committed by Manish Goregaokar
parent 9a6c06731f
commit e8f82c31c4

@ -68,6 +68,29 @@ fn main() {
}
```
Of course, while the analysis doesn't consider actual values, it does
have a relatively sophisticated understanding of dependencies and control
flow. For instance, this works:
```rust
let x: i32;
loop {
// Rust doesn't understand that this branch will be taken unconditionally,
// because it relies on actual values.
if true {
// But it does understand that it will only be taken once because
// we *do* unconditionally break out of it. Therefore `x` doesn't
// need to be marked as mutable.
x = 0;
break;
}
}
// It also knows that it's impossible to get here without reaching the break.
// And therefore that `x` must be initialized here!
println!("{}", x);
```
If a value is moved out of a variable, that variable becomes logically
uninitialized if the type of the value isn't Copy. That is:

@ -47,7 +47,7 @@ discriminant.
On non-C-like enums, this will inhibit certain optimizations like the null-
pointer optimization.
These reprs have no affect on a struct.
These reprs have no effect on a struct.

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