Merge branch 'master' of https://github.com/sunface/rust-by-practice
This commit is contained in:
commit
b669929771
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@ -6,10 +6,10 @@
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fn main() {
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let x = 5;
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// fill the blank
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// Fill the blank
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let p = __;
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println!("the memory address of x is {:p}", p); // one possible output: 0x16fa3ac84
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println!("the memory address of x is {:p}", p); // One possible output: 0x16fa3ac84
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}
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```
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@ -20,23 +20,23 @@ fn main() {
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let x = 5;
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let y = &x;
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// modify this line only
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// Modify this line only
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assert_eq!(5, y);
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println!("Success!")
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println!("Success!");
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}
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```
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3. 🌟
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```rust,editable
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// fix error
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// Fix error
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fn main() {
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let mut s = String::from("hello, ");
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borrow_object(s);
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println!("Success!")
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println!("Success!");
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}
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fn borrow_object(s: &String) {}
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@ -45,13 +45,13 @@ fn borrow_object(s: &String) {}
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4. 🌟
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```rust,editable
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// fix error
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// Fix error
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fn main() {
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let mut s = String::from("hello, ");
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push_str(s);
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println!("Success!")
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println!("Success!");
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}
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fn push_str(s: &mut String) {
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@ -65,16 +65,16 @@ fn push_str(s: &mut String) {
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fn main() {
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let mut s = String::from("hello, ");
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// fill the blank to make it work
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// Fill the blank to make it work
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let p = __;
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p.push_str("world");
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println!("Success!")
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println!("Success!");
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}
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```
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#### ref
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#### Ref
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`ref` can be used to take references to a value, similar to `&`.
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6. 🌟🌟🌟
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@ -84,18 +84,18 @@ fn main() {
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let c = '中';
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let r1 = &c;
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// fill the blank,dont change other code
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// Fill the blank,dont change other code
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let __ r2 = c;
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assert_eq!(*r1, *r2);
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// check the equality of the two address strings
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// Check the equality of the two address strings
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assert_eq!(get_addr(r1),get_addr(r2));
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println!("Success!")
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println!("Success!");
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}
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// get memory address string
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// Get memory address string
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fn get_addr(r: &char) -> String {
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format!("{:p}", r)
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}
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@ -105,8 +105,8 @@ fn get_addr(r: &char) -> String {
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7. 🌟
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```rust,editable
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// remove something to make it work
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// don't remove a whole line !
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// Remove something to make it work
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// Don't remove a whole line !
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fn main() {
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let mut s = String::from("hello");
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@ -115,21 +115,21 @@ fn main() {
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println!("{}, {}", r1, r2);
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println!("Success!")
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println!("Success!");
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}
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```
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#### Mutablity
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8. 🌟 Error: Borrow a immutable object as mutable
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#### Mutability
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8. 🌟 Error: Borrow an immutable object as mutable
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```rust,editable
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fn main() {
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//fix error by modifying this line
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// Fix error by modifying this line
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let s = String::from("hello, ");
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borrow_object(&mut s);
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println!("Success!")
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println!("Success!");
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}
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fn borrow_object(s: &mut String) {}
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@ -138,7 +138,7 @@ fn borrow_object(s: &mut String) {}
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9. 🌟🌟 Ok: Borrow a mutable object as immutable
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```rust,editable
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// this code has no errors!
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// This code has no errors!
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fn main() {
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let mut s = String::from("hello, ");
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@ -146,7 +146,7 @@ fn main() {
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s.push_str("world");
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println!("Success!")
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println!("Success!");
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}
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fn borrow_object(s: &String) {}
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@ -156,7 +156,7 @@ fn borrow_object(s: &String) {}
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10. 🌟🌟
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```rust,editable
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// comment one line to make it work
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// Comment one line to make it work
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fn main() {
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let mut s = String::from("hello, ");
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@ -178,8 +178,8 @@ fn main() {
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let r1 = &mut s;
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let r2 = &mut s;
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// add one line below to make a compiler error: cannot borrow `s` as mutable more than once at a time
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// you can't use r1 and r2 at the same time
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// Add one line below to make a compiler error: cannot borrow `s` as mutable more than once at a time
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// You can't use r1 and r2 at the same time
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}
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```
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@ -4,7 +4,7 @@
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```rust,editable
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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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// 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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@ -39,7 +39,7 @@ fn main() {
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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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// Convert String to Vec
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let _s = s.into_bytes();
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s
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}
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@ -47,7 +47,7 @@ fn give_ownership() -> String {
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4. 🌟🌟
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```rust,editable
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// fix the error without removing code line
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// Fix the error without removing code line
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fn main() {
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let s = String::from("hello, world");
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@ -63,7 +63,7 @@ fn print_str(s: String) {
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5. 🌟🌟
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```rust, editable
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// don't use clone ,use copy instead
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// 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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@ -80,12 +80,12 @@ Mutability can be changed when ownership is transferred.
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fn main() {
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let s = String::from("hello, ");
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// modify this line only !
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// Modify this line only !
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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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println!("Success!");
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}
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```
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@ -95,13 +95,13 @@ fn main() {
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fn main() {
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let x = Box::new(5);
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let ... // implement this line, dont change other lines!
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let ... // Implement this line, dont 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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println!("Success!");
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}
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```
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@ -148,7 +148,7 @@ fn main() {
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let _s = t.0;
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// modify this line only, don't use `_s`
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// Modify this line only, don't use `_s`
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println!("{:?}", t);
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}
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```
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@ -159,7 +159,7 @@ fn main() {
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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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// Fill the blanks
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let (__, __) = __;
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println!("{:?}, {:?}, {:?}", s1, s2, t); // -> "hello", "world", ("hello", "world")
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