fn _12_1(){
    println!("guide 12-1");

    let a = [1i32, 2i32, 3i32];
    let mut m = [2i32, 3i32, 4i32];
    if false {
      println!("{:?} {:?}", a, m);
    }

    let b = [0i32; 20]; // shorthand for array of 20 elements all initialized to 0
    println!("{:?}", b);
    m = [5i32, 6i32, 7i32];
    println!("{:?}", m);

    for i in m.iter() {
        println!("elem {}", i);
    }

    let names = ["Emilija", "Anzelika"];
    println!("{} -> {}", names[1], names[0]);
}

fn _12_2(){
    println!("guide 12-2");

    let mut v = vec![1i32, 2, 3];
    v.push(4);
    println!("{:?}, len is {}", v, v.len());
}

fn _12_3(){
    println!("guide 12-3");

    let mut a = vec![0i32, 1, 2, 3, 4];
    let middle = a.as_mut_slice();

    middle[0] = 10i32;

    for e in middle.iter() {
        println!("{}", e);
    }

}

fn main(){
    println!("guide 12");
    _12_1();
    _12_2();
    _12_3();
}

fn _12_1(){
    println!("guide 12-1");

    let a = [1i, 2i, 3i];
    let mut m = [2i, 3i, 4i];

    let b = [0i, ..20]; // shorthand for array of 20 elements all initialized to 0
    println!("{}", b);
    m = [5i, 6i, 7i];
    println!("{}", m);

    for i in m.iter() {
        println!("elem {}", i);
    }

    let names = ["Emilija", "Anzelika"];
    println!("{} -> {}", names[1], names[0]);
}

fn _12_2(){
    println!("guide 12-2");

    let mut v = vec![1i, 2, 3];
    v.push(4);
    println!("{}, len is {}", v, v.len());
}

fn _12_3(){
    println!("guide 12-3");

    let mut a = vec![0i, 1, 2, 3, 4];
    let middle = a.as_mut_slice(); 

    middle[0] = 10i;

    for e in middle.iter() {
        println!("{}", e);
    }

}

fn main(){
    println!("guide 12");
    _12_1();
    _12_2();
    _12_3();
}

--- 
+++ 
@@ -1,13 +1,16 @@
 fn _12_1(){
     println!("guide 12-1");
 
-    let a = [1i, 2i, 3i];
-    let mut m = [2i, 3i, 4i];
+    let a = [1i32, 2i32, 3i32];
+    let mut m = [2i32, 3i32, 4i32];
+    if false {
+      println!("{:?} {:?}", a, m);
+    }
 
-    let b = [0i, ..20]; // shorthand for array of 20 elements all initialized to 0
-    println!("{}", b);
-    m = [5i, 6i, 7i];
-    println!("{}", m);
+    let b = [0i32; 20]; // shorthand for array of 20 elements all initialized to 0
+    println!("{:?}", b);
+    m = [5i32, 6i32, 7i32];
+    println!("{:?}", m);
 
     for i in m.iter() {
         println!("elem {}", i);
@@ -20,18 +23,18 @@
 fn _12_2(){
     println!("guide 12-2");
 
-    let mut v = vec![1i, 2, 3];
+    let mut v = vec![1i32, 2, 3];
     v.push(4);
-    println!("{}, len is {}", v, v.len());
+    println!("{:?}, len is {}", v, v.len());
 }
 
 fn _12_3(){
     println!("guide 12-3");
 
-    let mut a = vec![0i, 1, 2, 3, 4];
-    let middle = a.as_mut_slice(); 
+    let mut a = vec![0i32, 1, 2, 3, 4];
+    let middle = a.as_mut_slice();
 
-    middle[0] = 10i;
+    middle[0] = 10i32;
 
     for e in middle.iter() {
         println!("{}", e);
Fix format trait errors (breaking change)
