error[E0015]: calls in constant functions are limited to constant functions

[haata]

rustc 1.50.0-nightly (7efc097c4 2020-12-12)

cargo build

   Compiling alloc-cortex-m v0.4.0 (/home/jacob/git/alloc-cortex-m)

Error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
  --> src/lib.rs:29:43
   |
29 |             heap: Mutex::new(RefCell::new(Heap::empty())),
   |                                           ^^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0015`.
error: could not compile `alloc-cortex-m`

This fixes the error, but I'm not sure if this follows the original intent:

diff --git a/src/lib.rs b/src/lib.rs
index 56d2305..338aa0a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -24,7 +24,7 @@ impl CortexMHeap {
     ///
     /// You must initialize this heap using the
     /// [`init`](struct.CortexMHeap.html#method.init) method before using the allocator.
-    pub const fn empty() -> CortexMHeap {
+    pub fn empty() -> CortexMHeap {
         CortexMHeap {
             heap: Mutex::new(RefCell::new(Heap::empty())),
         }

[thalesfragoso]

It seems that it was caused by rust-osdev/linked-list-allocator#43, I guess we could just enable the const_mut_refs feature on the linked-list-allocator crate, since this crate is basically nightly only.