Dangling pointer

A dangling pointer occurs when a reference points to memory that has been de-allocated, leading to undefined behaviour. This can happen if a reference outlives the data it points to, posing a risk of accessing invalid or freed memory

fn main() {
    let initial_text = String::from("Hi from main ");
    let second_text = improve();
    println!("{:?}", second_text);
}

fn improve()->&str{
    let ss = String::from("Helloo");
    &ss
}

error[E0106]: missing lifetime specifier
 --> src/main.rs:8:15
  |
8 | fn improve()->&str{
  |               ^ expected named lifetime
 parameter
  |
  = help: this function's return type conta
ins a borrowed value, but there is no value
 for it to be borrowed from
help: consider using the `'static` lifetime
  |
8 | fn improve()->&'static str{
  |                +++++++

For more information about this error, try 
`rustc --explain E0106`.
error: could not compile `dangling` (bin "d
angling") due to previous error

&’static

error[E0515]: cannot return reference to lo
cal variable `ss`
  --> src/main.rs:10:5
   |
10 |     &ss
   |     ^^^ returns a reference to data ow
ned by the current function

Solution (using static lifetime)

fn main() {
    let initial_text = String::from("Hi");
    let second_text = improve();
    println!("{:?}", second_text);
}

fn improve()->&'static str{
    let ss ="Helloo";
    ss
}

Solution 2

fn main() {
    let initial_text = String::from("Hi from main ");
    let second_text = improve();
    println!("{:?}", second_text);
}

fn improve()->String{
    let ss = String::from("Helloo");
    ss
}