Import https://github.com/tock/libtock-rs at commit 828c19d into third_party/libtock-drivers/.

third_party/libtock-drivers/src/result.rs

@@ -0,0 +1,69 @@
+use core::fmt;
+
+pub use libtock_core::result::*;
+
+pub type TockResult<T> = Result<T, TockError>;
+
+#[derive(Copy, Clone)]
+pub enum TockError {
+    Subscribe(SubscribeError),
+    Command(CommandError),
+    Allow(AllowError),
+    Format,
+    Other(OtherError),
+}
+
+#[cfg(not(any(target_arch = "arm", target_arch = "riscv32")))]
+impl core::fmt::Debug for TockError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        writeln!(f, "impl Debug only for test builds")
+    }
+}
+
+impl From<SubscribeError> for TockError {
+    fn from(subscribe_error: SubscribeError) -> Self {
+        TockError::Subscribe(subscribe_error)
+    }
+}
+
+impl From<CommandError> for TockError {
+    fn from(command_error: CommandError) -> Self {
+        TockError::Command(command_error)
+    }
+}
+
+impl From<AllowError> for TockError {
+    fn from(allow_error: AllowError) -> Self {
+        TockError::Allow(allow_error)
+    }
+}
+
+impl From<fmt::Error> for TockError {
+    fn from(fmt::Error: fmt::Error) -> Self {
+        TockError::Format
+    }
+}
+
+#[derive(Copy, Clone)]
+pub enum OtherError {
+    ButtonsDriverInvalidState,
+    GpioDriverInvalidState,
+    TimerDriverDurationOutOfRange,
+    TimerDriverErroneousClockFrequency,
+    DriversAlreadyTaken,
+    OutOfRange,
+}
+
+impl From<OtherError> for TockError {
+    fn from(other: OtherError) -> Self {
+        TockError::Other(other)
+    }
+}
+
+pub struct OutOfRangeError;
+
+impl From<OutOfRangeError> for TockError {
+    fn from(_: OutOfRangeError) -> Self {
+        TockError::Other(OtherError::OutOfRange)
+    }
+}