rust: pin-init: examples, tests: add conditional compilation in order to compile under any feature combination

In the CI, all examples & tests should be run under all feature
combinations. Currently several examples & tests use `std` without
conditionally enabling it. Thus make them all compile under any feature
combination by conditionally disabling the code that uses e.g. `std`.

Link: https://github.com/Rust-for-Linux/pin-init/pull/50/commits/fdfb70efddbc711b4543c850ee38a2f5a8d17cb6
Link: https://lore.kernel.org/all/20250523125424.192843-2-lossin@kernel.org
Signed-off-by: Benno Lossin <lossin@kernel.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/rust/pin-init/examples/pthread_mutex.rs b/rust/pin-init/examples/pthread_mutex.rs
index 5acc5108b954..c709dabba7eb 100644
--- a/rust/pin-init/examples/pthread_mutex.rs
+++ b/rust/pin-init/examples/pthread_mutex.rs
@@ -44,6 +44,7 @@ mod pthread_mtx {
     pub enum Error {
         #[allow(dead_code)]
         IO(std::io::Error),
+        #[allow(dead_code)]
         Alloc,
     }
 
@@ -61,6 +62,7 @@ mod pthread_mtx {
     }
 
     impl<T> PThreadMutex<T> {
+        #[allow(dead_code)]
         pub fn new(data: T) -> impl PinInit<Self, Error> {
             fn init_raw() -> impl PinInit<UnsafeCell<libc::pthread_mutex_t>, Error> {
                 let init = |slot: *mut UnsafeCell<libc::pthread_mutex_t>| {
@@ -103,6 +105,7 @@ mod pthread_mtx {
         }? Error)
         }
 
+        #[allow(dead_code)]
         pub fn lock(&self) -> PThreadMutexGuard<'_, T> {
             // SAFETY: raw is always initialized
             unsafe { libc::pthread_mutex_lock(self.raw.get()) };