refactor: replace internal const_assert! with std assert!

Author: paolobarbolini

src/secure/key.rs

@@ -4,9 +4,9 @@ const COMBINED_KEY_LENGTH: usize = SIGNING_KEY_LEN + ENCRYPTION_KEY_LEN;
 
 // Statically ensure the numbers above are in-sync.
 #[cfg(feature = "signed")]
-const_assert!(crate::secure::signed::KEY_LEN == SIGNING_KEY_LEN);
+const _: () = assert!(crate::secure::signed::KEY_LEN == SIGNING_KEY_LEN);
 #[cfg(feature = "private")]
-const_assert!(crate::secure::private::KEY_LEN == ENCRYPTION_KEY_LEN);
+const _: () = assert!(crate::secure::private::KEY_LEN == ENCRYPTION_KEY_LEN);
 
 /// A cryptographic master key for use with `Signed` and/or `Private` jars.
 ///

src/secure/macros.rs

@@ -38,15 +38,3 @@ macro_rules! assert_secure_behaviour {
         assert!($secure.get("secure").is_none());
     }};
 }
-
-// This is courtesty of `static_assertions`. That library is Copyright (c) 2017
-// Nikolai Vazquez. See https://github.com/nvzqz/static-assertions-rs for more.
-macro_rules! const_assert {
-    ($x:expr $(,)?) => {
-        #[allow(unknown_lints, clippy::eq_op)]
-        const _: [(); 0 - !{
-            const ASSERT: bool = $x;
-            ASSERT
-        } as usize] = [];
-    };
-}