[PATCH v1 22/28] rust: str: add `fmt!` macro

[Miguel Ojeda]

From: Wedson Almeida Filho <wedsonaf@xxxxxxxxx>

Add the `fmt!` macro, which is a convenience alias for the Rust
`core::format_args!` macro.

For instance, it may be used to create a `CString`:

    CString::try_from_fmt(fmt!("{}{}", "abc", 42))?

Signed-off-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxx>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
---
 rust/kernel/str.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 877148b77e71..ffac633423db 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -592,3 +592,9 @@ impl Deref for CString {
         unsafe { CStr::from_bytes_with_nul_unchecked(self.buf.as_slice()) }
     }
 }
+
+/// A convenience alias for [`core::format_args`].
+#[macro_export]
+macro_rules! fmt {
+    ($($f:tt)*) => ( core::format_args!($($f)*) )
+}
-- 
2.38.1