Use addr_of_mut! instead of as_ptr() to avoid shared reference to mutable static

Author: jannic

README.md

@@ -22,6 +22,7 @@ Starting with Rust 1.68, this crate can be used as a global allocator on stable
 
 extern crate alloc;
 
+use core::ptr::addr_of_mut;
 use cortex_m_rt::entry;
 use embedded_alloc::LlffHeap as Heap;
 
@@ -35,7 +36,7 @@ fn main() -> ! {
         use core::mem::MaybeUninit;
         const HEAP_SIZE: usize = 1024;
         static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
-        unsafe { HEAP.init(HEAP_MEM.as_ptr() as usize, HEAP_SIZE) }
+        unsafe { HEAP.init(addr_of_mut!(HEAP_MEM) as usize, HEAP_SIZE) }
     }
 
     // now the allocator is ready types like Box, Vec can be used.

examples/allocator_api.rs

@@ -7,6 +7,7 @@ extern crate alloc;
 use alloc::vec::Vec;
 use core::mem::MaybeUninit;
 use core::panic::PanicInfo;
+use core::ptr::addr_of_mut;
 use cortex_m_rt::entry;
 use embedded_alloc::LlffHeap as Heap;
 
@@ -20,7 +21,7 @@ fn main() -> ! {
     const HEAP_SIZE: usize = 16;
     static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
     let heap: Heap = Heap::empty();
-    unsafe { heap.init(HEAP_MEM.as_ptr() as usize, HEAP_SIZE) }
+    unsafe { heap.init(addr_of_mut!(HEAP_MEM) as usize, HEAP_SIZE) }
 
     let mut xs = Vec::new_in(heap);
     xs.push(1);

examples/global_alloc.rs

@@ -5,6 +5,7 @@ extern crate alloc;
 
 use alloc::vec::Vec;
 use core::panic::PanicInfo;
+use core::ptr::addr_of_mut;
 use cortex_m_rt::entry;
 // Linked-List First Fit Heap allocator (feature = "llff")
 use embedded_alloc::LlffHeap as Heap;
@@ -21,7 +22,7 @@ fn main() -> ! {
         use core::mem::MaybeUninit;
         const HEAP_SIZE: usize = 1024;
         static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
-        unsafe { HEAP.init(HEAP_MEM.as_ptr() as usize, HEAP_SIZE) }
+        unsafe { HEAP.init(addr_of_mut!(HEAP_MEM) as usize, HEAP_SIZE) }
     }
 
     let mut xs = Vec::new();

examples/llff_integration_test.rs

@@ -21,6 +21,7 @@ extern crate panic_semihosting;
 
 use alloc::vec::Vec;
 use core::mem::{size_of, MaybeUninit};
+use core::ptr::addr_of_mut;
 use cortex_m_rt::entry;
 use cortex_m_semihosting::{debug, hprintln};
 use embedded_alloc::LlffHeap as Heap;
@@ -66,7 +67,7 @@ fn main() -> ! {
     {
         const HEAP_SIZE: usize = 1024;
         static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
-        unsafe { HEAP.init(HEAP_MEM.as_ptr() as usize, HEAP_SIZE) }
+        unsafe { HEAP.init(addr_of_mut!(HEAP_MEM) as usize, HEAP_SIZE) }
     }
 
     #[allow(clippy::type_complexity)]

examples/tlsf_integration_test.rs

@@ -21,6 +21,7 @@ extern crate panic_semihosting;
 
 use alloc::collections::LinkedList;
 use core::mem::MaybeUninit;
+use core::ptr::addr_of_mut;
 use cortex_m_rt::entry;
 use cortex_m_semihosting::{debug, hprintln};
 use embedded_alloc::TlsfHeap as Heap;
@@ -83,7 +84,7 @@ fn test_allocator_api() {
 fn main() -> ! {
     {
         static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
-        unsafe { HEAP.init(HEAP_MEM.as_ptr() as usize, HEAP_SIZE) }
+        unsafe { HEAP.init(addr_of_mut!(HEAP_MEM) as usize, HEAP_SIZE) }
     }
 
     #[allow(clippy::type_complexity)]