Switch from lazy_static to once_cell

Once_cell has better no_std support

Cargo.toml

@@ -22,9 +22,9 @@ maintenance = { status = "actively-developed" }
 default = ["std", "atomic"]
 std = []
 atomic = ["spin"]
-atomic-polyfill = ["dep:atomic-polyfill"]
+atomic-polyfill = ["once_cell/atomic-polyfill", "dep:atomic-polyfill"]
 # Enables derive(Bundle)
-macros = ["hecs-macros", "lazy_static"]
+macros = ["hecs-macros", "once_cell"]
 # Enables the serialize::column module
 column-serialize = ["serde"]
 # Enables the serialize::row module
@@ -34,7 +34,7 @@ row-serialize = ["serde"]
 atomic-polyfill = { version = "0.1.7", optional = true }
 hecs-macros = { path = "macros", version = "0.8.2", optional = true }
 hashbrown = { version = "0.12.0", default-features = false, features = ["ahash", "inline-more"] }
-lazy_static = { version = "1.4.0", optional = true, features = ["spin_no_std"] }
+once_cell = { version = "1.12.0", default-features = false, optional = true, features = ["alloc"] }
 serde = { version = "1.0.117", default-features = false, optional = true }
 spin = { version = "0.9.2", default-features = false, optional = true, features = ["mutex", "spin_mutex"] }
 

macros/src/bundle.rs

@@ -89,12 +89,10 @@ fn gen_bundle_impl(
     };
     let with_static_ids_body = if generics.params.is_empty() {
         quote! {
-            ::hecs::lazy_static::lazy_static! {
-                static ref ELEMENTS: [::std::any::TypeId; #num_tys] = {
-                    #with_static_ids_inner
-                };
-            }
-            f(&*ELEMENTS)
+            static ELEMENTS: ::hecs::once_cell::race::OnceBox<[::core::any::TypeId; #num_tys]> = ::hecs::once_cell::race::OnceBox::new();
+            f(ELEMENTS.get_or_init(||
+                ::hecs::alloc::boxed::Box::new(#with_static_ids_inner)
+            ))
         }
     } else {
         quote! {

src/lib.rs

@@ -97,7 +97,7 @@ pub use archetype::TypeInfo;
 pub use bundle::DynamicClone;
 #[cfg(feature = "macros")]
 #[doc(hidden)]
-pub use lazy_static;
+pub use once_cell;
 #[doc(hidden)]
 pub use query::Fetch;