Questions tagged [lazy-static]
28 questions
1
vote
0 answers
Accessing disjoint entries in global HashMap for lifetime of thread in Rust
my current project requires recording some information for various events that happen during the execution of a thread. These events are saved in a global struct index by the thread id:
RECORDER1: HashMap> =…
gatoWololo
- 296
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1
vote
1 answer
What is better in Rust: defining a static variable to access it globally or passing a non-static variable through function arguments?
If a variable is used in multiple functions in a file, is it better to define it as static rather than passing a non-static variable through function arguments? Does this have a performance impact?
An example using a static variable:
lazy_static! {
…
Átila Gama Silva
- 33
- 1
- 5
1
vote
2 answers
Rust lazy static custom struct instance
In Rust, I am trying to declare a static instance of a custom struct.
Because by default I am not able to assign other values than const ones, I am trying to use lazy_static.
Here is my custom struct:
pub struct MyStruct {
field1: String,
…
Adrien Chapelet
- 386
- 4
- 24
0
votes
0 answers
error[E0432]: unresolved import `lazy_static`
i have this code :
which gives me error when trying to : cargo build
The error:
cargo build
Compiling front_end v0.1.0 (C:\dev\my\rust\workspace\front_end)
error[E0432]: unresolved import `lazy_static`
--> src\main.rs:4:5
|
4 | use…
user63898
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0
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1 answer
Why does this return statement cause an error but the return expression doesn't in Rust?
I'm confused why this code works below:
lazy_static! {
static ref TSS: TaskStateSegment = {
let mut tss = TaskStateSegment::new();
tss.interrupt_stack_table[DOUBLE_FAULT_IST_INDEX as usize] = {
const…
0
votes
0 answers
Stateful embedded library in Rust
I want to develop a library in Rust for microcontrollers that holds some state information.
This state data cannot be transferred to the caller of the library. I am using #![no_std]. The library should be suitable for bare metal applications and…
Stefan
- 83
- 8
0
votes
2 answers
no rules expected this token in macro call during initialization of static variable using lazy_static crate
I am trying to initialize a static variable at runtime using lazy_static crate. But I'm getting no rules expected the token E1 error while compiling. This is the link lazy_static I followed
use lazy_static::lazy_static;
lazy_static! {
static…
Harry
- 2,177
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0
votes
1 answer
The item's lifetime of global HashMap by lazy_static in Rust
I am new to Rust.
I define a global HashMap of User by lazy_static.
There is a lifetime in User, so I have to set a lifetime in lazy_static. It seems that only 'static can be used in lazy_static.
Here is the question: can I insert "non-static" User…
Bingzheng Wu
- 435
- 3
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0
votes
1 answer
Get item's reference from global HashMap in Rust
I'm trying to use a static HashMap to store some data that I want to use and modify globally in the future. I found out that some way of declaring such a global map is by using lazy_static and mutex in order to share data safely.…
Hèctor M.C.
- 95
- 1
- 6
0
votes
0 answers
Rust: Why is lazy_static not working with some types
I need to create some global mutable variables, using lazy_static! with some types works, but with some other types it doesn't. The mutex is to change value.
This works:
lazy_static! {
static ref foo: Mutex:…
Dee
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0
votes
1 answer
What type should I use to return a lazy_static value?
I plan to have a struct which provides the JSON schema via a trait method.
The schema is stored compiled in a lazy_static variable, but which type does my schema() function have to return?
lazy_static::lazy_static! {
static ref DEF:…
macalloy
- 43
- 7
0
votes
1 answer
Rust lazy_static variable RwLock access
I am trying to declare and read/write an instance of a custom struct, using lazy_static as I had to use non-const function at its initialization (string).
As I saw here in an other Stackoverflow post, I tried to use RwLock, which works fine when it…
Adrien Chapelet
- 386
- 4
- 24
-1
votes
1 answer
How to preload lazy_static variables in Rust?
I use Rust's lazy_static crate to assign a frequently used database object to a global variable but I do not want lazy loading. Is there a way to trigger lazy_static to preload the variable or is there a better way to achieve this? All the functions…
Konrad Höffner
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