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auto merge of #16175 : EduardoBautista/rust/fix-guessing-game-appeari…
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…ng-early, r=steveklabnik

Solves: #16162
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bors committed Aug 2, 2014
2 parents 1b44c5b + 69267b1 commit 5bad333
Showing 1 changed file with 14 additions and 14 deletions.
28 changes: 14 additions & 14 deletions src/doc/guide.md
Expand Up @@ -449,9 +449,9 @@ let x;
...we'll get an error:

```{ignore}
src/guessing_game.rs:2:9: 2:10 error: cannot determine a type for this local variable: unconstrained type
src/guessing_game.rs:2 let x;
^
src/hello_world.rs:2:9: 2:10 error: cannot determine a type for this local variable: unconstrained type
src/hello_world.rs:2 let x;
^
```

Giving it a type will compile, though:
Expand All @@ -460,7 +460,7 @@ Giving it a type will compile, though:
let x: int;
```

Let's try it out. Change your `src/guessing_game.rs` file to look like this:
Let's try it out. Change your `src/hello_world.rs` file to look like this:

```{rust}
fn main() {
Expand All @@ -474,10 +474,10 @@ You can use `cargo build` on the command line to build it. You'll get a warning,
but it will still print "Hello, world!":

```{ignore,notrust}
Compiling guessing_game v0.1.0 (file:/home/you/projects/guessing_game)
src/guessing_game.rs:2:9: 2:10 warning: unused variable: `x`, #[warn(unused_variable)] on by default
src/guessing_game.rs:2 let x: int;
^
Compiling hello_world v0.1.0 (file:/home/you/projects/hello_world)
src/hello_world.rs:2:9: 2:10 warning: unused variable: `x`, #[warn(unused_variable)] on by default
src/hello_world.rs:2 let x: int;
^
```

Rust warns us that we never use the variable binding, but since we never use it,
Expand All @@ -496,16 +496,16 @@ And try to build it. You'll get an error:

```{bash}
$ cargo build
Compiling guessing_game v0.1.0 (file:/home/you/projects/guessing_game)
src/guessing_game.rs:4:39: 4:40 error: use of possibly uninitialized variable: `x`
src/guessing_game.rs:4 println!("The value of x is: {}", x);
^
Compiling hello_world v0.1.0 (file:/home/you/projects/hello_world)
src/hello_world.rs:4:39: 4:40 error: use of possibly uninitialized variable: `x`
src/hello_world.rs:4 println!("The value of x is: {}", x);
^
note: in expansion of format_args!
<std macros>:2:23: 2:77 note: expansion site
<std macros>:1:1: 3:2 note: in expansion of println!
src/guessing_game.rs:4:5: 4:42 note: expansion site
src/hello_world.rs:4:5: 4:42 note: expansion site
error: aborting due to previous error
Could not execute process `rustc src/guessing_game.rs --crate-type bin --out-dir /home/you/projects/guessing_game/target -L /home/you/projects/guessing_game/target -L /home/you/projects/guessing_game/target/deps` (status=101)
Could not execute process `rustc src/hello_world.rs --crate-type bin --out-dir /home/you/projects/hello_world/target -L /home/you/projects/hello_world/target -L /home/you/projects/hello_world/target/deps` (status=101)
```

Rust will not let us use a value that has not been initialized. So why let us
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