Added struct de-structure-ing example in tips & tricks

This commit is contained in:
Emil Fresk 2019-11-07 14:12:16 +01:00
parent 72e84cb297
commit 76e234599f
2 changed files with 56 additions and 0 deletions

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@ -165,3 +165,12 @@ crate and print the output to the console.
$ # produces the same output as before
$ cargo expand --example smallest | tail
```
## Resource de-structure-ing
When having a task taking multiple resources it can help in readability to split
up the resource struct. Here're two examples on how this can be done:
``` rust
{{#include ../../../../examples/destructure.rs}}
```

47
examples/destructure.rs Normal file
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@ -0,0 +1,47 @@
//! examples/destructure.rs
#![deny(unsafe_code)]
#![deny(warnings)]
#![no_main]
#![no_std]
use cortex_m_semihosting::hprintln;
use lm3s6965::Interrupt;
use panic_semihosting as _;
#[rtfm::app(device = lm3s6965)]
const APP: () = {
struct Resources {
// Some resources to work with
#[init(0)]
a: u32,
#[init(0)]
b: u32,
#[init(0)]
c: u32,
}
#[init]
fn init(_: init::Context) {
rtfm::pend(Interrupt::UART0);
rtfm::pend(Interrupt::UART1);
}
// Direct destructure
#[task(binds = UART0, resources = [a, b, c])]
fn uart0(cx: uart0::Context) {
let a = cx.resources.a;
let b = cx.resources.b;
let c = cx.resources.c;
hprintln!("UART0: a = {}, b = {}, c = {}", a, b, c).unwrap();
}
// De-structure-ing syntax
#[task(binds = UART1, resources = [a, b, c])]
fn uart1(cx: uart1::Context) {
let uart1::Resources { a, b, c } = cx.resources;
hprintln!("UART0: a = {}, b = {}, c = {}", a, b, c).unwrap();
}
};