@@ -120,3 +120,25 @@ macro_rules! assert_match {
);
};
}
+
+/// Assert at compile time that an expression is true. This is similar
+/// to `const { assert!(...); }` but it works outside functions, as well as
+/// on versions of Rust before 1.79.
+///
+/// # Examples
+///
+/// ```
+/// # use qemu_api::const_assert;
+/// const_assert!("abc".len() == 3);
+/// ```
+///
+/// ```compile_fail
+/// # use qemu_api::const_assert;
+/// const_assert!("abc".len() == 2); // does not compile
+/// ```
+#[macro_export]
+macro_rules! const_assert {
+ ($x:expr) => {
+ const _: [(); { const VALUE__: bool = $x; VALUE__ as usize }] = [()];
+ };
+}
Add a new assertion that is similar to "const { assert!(...) }" but can be used outside functions and with older versions of Rust. Similar in concept (but not in code) to the homonymous macro of the "static_assertions" crate. Suggested-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- rust/qemu-api/src/assertions.rs | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)