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Contradictory "missing lifetime specifier" error on owned value

By : عبد الرحمن إيهاب
Date : October 15 2020, 08:10 AM
around this issue I wrote code to model the following structure, where a node has a reference to its parent node: , Your defintion of node is
code :
struct Node<'a>
fn new(parent: &'a Node) -> Node<'a>;
struct Node<'a> {
    parent: &'a Node<'a>,

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"missing type specifier" error on constructor declaration

By : mrak
Date : March 29 2020, 07:55 AM
This might help you You can't have circular #includes (one file #includes another which #includes the first file). Forward declaring one of the classes instead of the #include will break the chain and allow it to work. Declaring the class name allows you to use the name without having to know about the internal bits of the class.
BTW, the desire for circular #includes is a design smell. Perhaps you could create an interface that the two classes can depend on instead? Then they won't have to mutually depend on each other.

Getting 'Missing Lifetime specifier' error

By : user3771101
Date : March 29 2020, 07:55 AM
hop of those help? First, note that &T/&mut T and *const T/*mut T are different types of pointers in Rust. The former are called "references" and they are statically checked in various ways (including borrowing analysis) and they can't be null or point to some invalid object. The latter are called "raw pointers" and are used primarily in abstractions implementations and for FFI.
Consequently, writing
code :
Query {
    data: name,
    prev: ptr::null(),
    next: ptr::null(),
let x: &str = "hello";

fn print_str(s: &str) { println!("{}", s); }
struct Query<'a, T> {
    data: T,
    prev: &'a Query<'a, T>,
    next: &'a Query<'a, T>,
let mut x = SomeStructure(None);
let y = SomeStructure(Some(&x));
x.0 = Some(&y);

What does "missing lifetime specifier" mean when storing a &str in a structure?

By : GetRandom
Date : March 29 2020, 07:55 AM
Hope that helps "Missing lifetime specifier" means that in the struct definition, you haven't told it how long the reference to the string slice is allowed to stay around. In order for your code to be safe, it has to stick around for at least as long as the struct.
You need to define a lifetime parameter on your struct and use it for the string slice.
code :
struct Excel<'a> {
    columns: HashMap<&'a str, Vec<f64>>
struct Excel {
    columns: HashMap<String, Vec<f64>>

Why do I get "missing lifetime specifier" or "wrong number of type arguments" when implementing a tr

By : Ebony Low Key Hill
Date : March 29 2020, 07:55 AM
I wish this helpful for you The error messages seem pretty clear to me. They point at a type and state that the type needs a lifetime or a type. Add them:
code :
impl<'a> Bar1<'a> for Foo1<'a> { /* ... */ }
impl<T> Bar2<T> for Foo2<T> { /* ... */ }
impl<'a, T: 'a> Bar3<'a, T> for Foo3<'a, T> { /* ... */ }
pub trait Bar3<'a, T: 'a> {
//            ^^^^^^^^^^^
    fn baaar(&self);

error[E0106]: missing lifetime specifier (despite it being set)

By : Arunkumar Yadav
Date : March 29 2020, 07:55 AM
fixed the issue. Will look into that further Consider the following code: , I got an answer on #rust-beginners IRC channel:
code :
fn parse_argv() -> clap::ArgMatches<'static> {
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