From 51540739c55f2124e8fee0b68621bc6e28271ff9 Mon Sep 17 00:00:00 2001
From: Mads Marquart <mads@marquart.dk>
Date: Wed, 4 Sep 2024 12:51:43 +0200
Subject: [PATCH] Prepare for making the crate `no_std`

---
 Cargo.toml | 5 +++++
 src/lib.rs | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index 124b520..334263d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,6 +11,11 @@ keywords = ["window", "metal", "graphics"]
 categories = ["game-engines", "graphics"]
 exclude = [".github/*"]
 
+[features]
+default = ["std"]
+std = ["alloc"]
+alloc = []
+
 [target.'cfg(target_vendor = "apple")'.dependencies]
 objc2 = "0.5.2"
 objc2-foundation = { version = "0.2.2", features = [
diff --git a/src/lib.rs b/src/lib.rs
index dd41f65..66c059b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -124,6 +124,7 @@
 //! do not modify common `CALayer` properties of the layer that `raw-window-metal` creates, since
 //! they may just end up being overwritten (see also "Semantics" above).
 
+#![no_std]
 #![cfg(target_vendor = "apple")]
 #![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg_hide), doc(cfg_hide(doc)))]
 #![deny(unsafe_op_in_unsafe_fn)]
@@ -142,6 +143,12 @@ use objc2::{msg_send_id, ClassType};
 use objc2_foundation::{MainThreadMarker, NSObject, NSObjectProtocol};
 use objc2_quartz_core::{CALayer, CAMetalLayer};
 
+#[cfg(not(feature = "alloc"))]
+compile_error!("The `alloc` feature must currently be enabled.");
+
+#[cfg(not(feature = "std"))]
+compile_error!("The `std` feature must currently be enabled.");
+
 /// A wrapper around [`CAMetalLayer`].
 #[doc(alias = "CAMetalLayer")]
 #[derive(Debug, Clone)]