From 36a9243efa67a37b5a690e44234f0ccca74e8209 Mon Sep 17 00:00:00 2001
From: Tom Dohrmann <erbse.13@gmx.de>
Date: Thu, 2 Dec 2021 21:54:15 +0100
Subject: [PATCH] remove `const_assert!` in favor of std's `assert!`

---
 src/addr.rs           |  4 ++--
 src/lib.rs            | 14 --------------
 src/structures/gdt.rs |  2 +-
 3 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/src/addr.rs b/src/addr.rs
index d796a0e35..b71d7b63d 100644
--- a/src/addr.rs
+++ b/src/addr.rs
@@ -544,7 +544,7 @@ impl Sub<PhysAddr> for PhysAddr {
 /// feature, the panic message will be "index out of bounds".
 #[inline]
 pub const fn align_down(addr: u64, align: u64) -> u64 {
-    const_assert!(align.is_power_of_two(), "`align` must be a power of two");
+    assert!(align.is_power_of_two(), "`align` must be a power of two");
     addr & !(align - 1)
 }
 
@@ -556,7 +556,7 @@ pub const fn align_down(addr: u64, align: u64) -> u64 {
 /// feature, the panic message will be "index out of bounds".
 #[inline]
 pub const fn align_up(addr: u64, align: u64) -> u64 {
-    const_assert!(align.is_power_of_two(), "`align` must be a power of two");
+    assert!(align.is_power_of_two(), "`align` must be a power of two");
     let align_mask = align - 1;
     if addr & align_mask == 0 {
         addr // already aligned
diff --git a/src/lib.rs b/src/lib.rs
index 652dd5130..4a6cda74d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,7 +2,6 @@
 //! and access to various system registers.
 
 #![cfg_attr(not(test), no_std)]
-#![cfg_attr(feature = "const_fn", feature(const_panic))] // Better panic messages
 #![cfg_attr(feature = "const_fn", feature(const_mut_refs))] // GDT add_entry()
 #![cfg_attr(feature = "const_fn", feature(const_fn_fn_ptr_basics))] // IDT new()
 #![cfg_attr(feature = "const_fn", feature(const_fn_trait_bound))] // PageSize marker trait
@@ -45,19 +44,6 @@ macro_rules! const_fn {
     };
 }
 
-// Helper method for assert! in const fn. Uses out of bounds indexing if an
-// assertion fails and the "const_fn" feature is not enabled.
-#[cfg(feature = "const_fn")]
-macro_rules! const_assert {
-    ($cond:expr, $($arg:tt)+) => { assert!($cond, $($arg)*) };
-}
-#[cfg(not(feature = "const_fn"))]
-macro_rules! const_assert {
-    ($cond:expr, $($arg:tt)+) => {
-        [(); 1][!($cond as bool) as usize]
-    };
-}
-
 #[cfg(all(feature = "instructions", feature = "external_asm"))]
 pub(crate) mod asm;
 
diff --git a/src/structures/gdt.rs b/src/structures/gdt.rs
index 4911146a8..6ea977af9 100644
--- a/src/structures/gdt.rs
+++ b/src/structures/gdt.rs
@@ -72,7 +72,7 @@ impl GlobalDescriptorTable {
         let mut table = [0; 8];
         let mut idx = 0;
 
-        const_assert!(
+        assert!(
             next_free <= 8,
             "initializing a GDT from a slice requires it to be **at most** 8 elements."
         );