From ca4603ff028b8768f8eef28ec0fab48d29aaa976 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Mon, 18 Jul 2022 11:04:52 +0200
Subject: [PATCH] Add 'static_assert' macro

---
 src/lib.rs                 |  1 +
 src/utils/mod.rs           |  2 ++
 src/utils/static_assert.rs | 28 ++++++++++++++++++++++++++++
 3 files changed, 31 insertions(+)
 create mode 100644 src/utils/mod.rs
 create mode 100644 src/utils/static_assert.rs

diff --git a/src/lib.rs b/src/lib.rs
index 667c357..3593172 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1 +1,2 @@
 pub mod board;
+pub mod utils;
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
new file mode 100644
index 0000000..2833a48
--- /dev/null
+++ b/src/utils/mod.rs
@@ -0,0 +1,2 @@
+pub mod static_assert;
+pub use static_assert::*;
diff --git a/src/utils/static_assert.rs b/src/utils/static_assert.rs
new file mode 100644
index 0000000..81b7a86
--- /dev/null
+++ b/src/utils/static_assert.rs
@@ -0,0 +1,28 @@
+//! Static assert.
+
+/// Assert a condition at compile-time.
+///
+/// See [RFC 2790] for potential addition into Rust itself.
+///
+/// [RFC 2790]: https://github.com/rust-lang/rfcs/issues/2790
+///
+/// # Examples
+///
+/// ```
+/// use seer::utils::static_assert;
+///
+/// static_assert!(42 > 0);
+/// ```
+#[macro_export]
+macro_rules! static_assert {
+    ($condition:expr) => {
+        // Based on the latest one in `rustc`'s one before it was [removed].
+        //
+        // [removed]: https://github.com/rust-lang/rust/commit/c2dad1c6b9f9636198d7c561b47a2974f5103f6d
+        #[allow(dead_code)]
+        const _: () = [()][!($condition) as usize];
+    };
+}
+
+// I want it namespaced, even though it is exported to the root of the crate by `#[macro_export]`.
+pub use static_assert;