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<main>
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<h1 id="ownership"><a class="header" href="#ownership">Ownership</a></h1>
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<ol>
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<li>🌟🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">
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fn main() {
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// Use as many approaches as you can to make it work
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let x = String::from("Hello world");
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let y = x;
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println!("{}, {}",x, y);
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}</code></pre></pre>
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<ol start="2">
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<li>🌟🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">// Don't modify code in main!
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fn main() {
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let s1 = String::from("Hello world");
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let s2 = take_ownership(s1);
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println!("{}", s2);
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}
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// Only modify the code below!
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fn take_ownership(s: String) {
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println!("{}", s);
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}</code></pre></pre>
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<ol start="3">
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<li>🌟🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">
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fn main() {
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let s = give_ownership();
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println!("{}", s);
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}
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// Only modify the code below!
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fn give_ownership() -> String {
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let s = String::from("Hello world");
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// Convert String to Vec
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let _s = s.into_bytes();
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s
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}</code></pre></pre>
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<ol start="4">
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<li>🌟🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">// Fix the error without removing any code
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fn main() {
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let s = String::from("Hello World");
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print_str(s);
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println!("{}", s);
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}
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fn print_str(s: String) {
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println!("{}",s)
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}</code></pre></pre>
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<ol start="5">
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<li>🌟🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">// Don't use clone ,use copy instead
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fn main() {
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let x = (1, 2, (), "hello".to_string());
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let y = x.clone();
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println!("{:?}, {:?}", x, y);
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}</code></pre></pre>
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<h4 id="mutability"><a class="header" href="#mutability">Mutability</a></h4>
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<p>Mutability can be changed when ownership is transferred.</p>
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<ol start="6">
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<li>🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">
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// make the necessary variable mutable
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fn main() {
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let s = String::from("Hello ");
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let s1 = s;
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s1.push_str("World!");
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println!("Success!");
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}</code></pre></pre>
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<ol start="7">
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<li>🌟🌟🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">
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fn main() {
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let x = Box::new(5);
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let ... // update this line, don't change other lines!
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*y = 4;
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assert_eq!(*x, 5);
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println!("Success!");
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}</code></pre></pre>
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<h3 id="partial-move"><a class="header" href="#partial-move">Partial move</a></h3>
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<p>Within the destructuring of a single variable, both by-move and by-reference pattern bindings can be used at the same time. Doing this will result in a partial move of the variable, which means that parts of the variable will be moved while other parts stay. In such a case, the parent variable cannot be used afterwards as a whole, however the parts that are only referenced (and not moved) can still be used.</p>
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<h4 id="example"><a class="header" href="#example">Example</a></h4>
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<pre><pre class="playground"><code class="language-rust editable edition2021">
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fn main() {
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#[derive(Debug)]
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struct Person {
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name: String,
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age: Box<u8>,
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}
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let person = Person {
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name: String::from("Alice"),
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age: Box::new(20),
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};
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// `name` is moved out of person, but `age` is referenced
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let Person { name, ref age } = person;
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println!("The person's age is {}", age);
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println!("The person's name is {}", name);
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// Error! borrow of partially moved value: `person` partial move occurs
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//println!("The person struct is {:?}", person);
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// `person` cannot be used but `person.age` can be used as it is not moved
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println!("The person's age from person struct is {}", person.age);
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}</code></pre></pre>
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<h4 id="exercises"><a class="header" href="#exercises">Exercises</a></h4>
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<ol start="8">
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<li>🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">
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fn main() {
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let t = (String::from("hello"), String::from("world"));
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let _s = t.0;
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// Modify this line only, don't use `_s`
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println!("{:?}", t);
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}</code></pre></pre>
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<ol start="9">
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<li>🌟🌟</li>
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</ol>
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<pre><pre class="playground"><code class="language-rust editable edition2021">
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fn main() {
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let t = (String::from("hello"), String::from("world"));
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// Fill the blanks
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let (__, __) = __;
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println!("{:?}, {:?}, {:?}", s1, s2, t); // -> "hello", "world", ("hello", "world")
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}</code></pre></pre>
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<blockquote>
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<p>You can find the solutions <a href="https://github.com/sunface/rust-by-practice/blob/master/solutions/ownership/ownership.md">here</a>(under the solutions path), but only use it when you need it</p>
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