reference_borrowing

12-references_borrowing/Cargo.toml

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+[package]
+name = "references_borrowing"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

12-references_borrowing/src/main.rs

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+fn main() 
+    {
+        println!("Hello, world!");
+
+        //We can not have another reference, if we have a mutable one
+            let mut s1 = String::from("Safe");
+            let r1 = &s1;
+            let r2 = &s1;
+            //If an unmutable reference will be used, we can not have mutable one 
+                //let r3 = &mut s2;
+                //println!("References = {}-{}-{}", r1, r2, r3);
+            println!("References = {}-{}", r1, r2);
+            //r1 and r2 aren't going to be used, so we are free to have mutable reference
+            let r3 = &mut s1;
+            //One mutable reference will be used, we can not have another
+                //let r4 = &mut s2;
+                //println!("New References = {}-{}", r3, r4);
+            println!("New Mutable Reference = {}", r3);
+            //r3 isn't going to use anymore, we are free again to have another mutable reference
+            let r4 = &mut s1;
+            println!("New Mutable Reference Again = {}", r4);
+
+        let mut s2 = String::from("Traveler");
+        //No need to copy same values, or return anything
+        //Because we do not give owenership, just borrowing
+            borrow1(&s2);
+            borrow2(&mut s2);
+            println!("s2 = {}", s2);
+        //Because of unallocation after scope, this reference would be refered unallocated place
+        //Rust checks this, while compling to save us from runtime error
+            //let dangle_reference = dangling();
+    }
+fn borrow1(string_reference : &String)
+    {
+        println!("Length of String is = {}", string_reference.len());
+    }
+fn borrow2(string_reference : &mut String)
+    {
+        string_reference.push_str(" Code");
+    }
+/*fn dangling() -> &String
+    {
+        let mut some_string = String::from("Are we dangle ?");
+        &some_string
+    }*/