refactor(Clock): Allow immutable Clock objects

Changed `now(&mut self)` to `now(&self)`

Author: PTaylor-us

examples/nrf52_dk/main.rs

@@ -38,7 +38,7 @@ impl time::Clock for SysClock {
     type Rep = u64;
     const PERIOD: time::Period = <time::Period>::new(1, 16_000_000);
 
-    fn now(&mut self) -> time::Instant<Self> {
+    fn now(&self) -> time::Instant<Self> {
         self.capture_task.tasks_trigger[0].write(|write| unsafe { write.bits(1) });
 
         let ticks =

src/clock.rs

@@ -1,3 +1,5 @@
+//! The `Clock` trait can be implemented over hardware timers or other time-keeping device
+
 use crate::{time_int::TimeInt, Duration, Instant, Period};
 use core::convert::TryFrom;
 
@@ -10,10 +12,10 @@ pub trait Clock: Sized {
     const PERIOD: Period;
 
     /// Get the current Instant
-    fn now(&mut self) -> Instant<Self>;
+    fn now(&self) -> Instant<Self>;
 
     /// Blocking delay
-    fn delay<Dur: Duration>(&mut self, dur: Dur)
+    fn delay<Dur: Duration>(&self, dur: Dur)
     where
         Self::Rep: TryFrom<Dur::Rep>,
     {

src/instant.rs

@@ -38,7 +38,7 @@ impl<Clock: crate::Clock> Instant<Clock> {
     ///     type Rep = u32;
     ///     const PERIOD: Period = <Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// assert_eq!(Instant::<Clock>::new(5).duration_since::<Microseconds<u64>>(&Instant::<Clock>::new(3)),
@@ -74,7 +74,7 @@ impl<Clock: crate::Clock> Instant<Clock> {
     ///     type Rep = u32;
     ///     const PERIOD: Period =<Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// assert_eq!(Instant::<Clock>::new(5).duration_until::<Microseconds<u64>>(&Instant::<Clock>::new(7)),
@@ -138,7 +138,7 @@ impl<Clock: crate::Clock> PartialOrd for Instant<Clock> {
     ///     type Rep = u32;
     ///     const PERIOD: Period =<Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// assert!(Instant::<Clock>::new(5) > Instant::<Clock>::new(3));
@@ -178,7 +178,7 @@ where
     ///     type Rep = u32;
     ///     const PERIOD: Period =<Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// Instant::<Clock>::new(1) + Seconds(u32::MAX);
@@ -194,7 +194,7 @@ where
     ///     type Rep = u32;
     ///     const PERIOD: Period =<Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// let _ = Instant::<Clock>::new(0) + Milliseconds(i32::MAX as u32 + 1);
@@ -211,7 +211,7 @@ where
     ///     type Rep = u32;
     ///     const PERIOD: Period =<Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// assert_eq!(Instant::<Clock>::new(1) + Seconds(3_u32), Instant::<Clock>::new(3_001));
@@ -251,7 +251,7 @@ where
     ///     type Rep = u32;
     ///     const PERIOD: Period =<Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// Instant::<Clock>::new(1) - Seconds(u32::MAX);
@@ -267,7 +267,7 @@ where
     ///     type Rep = u32;
     ///     const PERIOD: Period = <Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// let _ = Instant::<Clock>::new(u32::MAX) - Milliseconds(i32::MAX as u32 + 1);
@@ -284,7 +284,7 @@ where
     ///     type Rep = u32;
     ///     const PERIOD: Period =<Period>::new(1, 1_000);
     ///     // ...
-    /// # fn now(&mut self) -> Instant<Self> {unimplemented!()}
+    /// # fn now(&self) -> Instant<Self> {unimplemented!()}
     /// }
     ///
     /// assert_eq!(Instant::<Clock>::new(800) - Milliseconds(700_u32), Instant::<Clock>::new(100));
@@ -315,7 +315,7 @@ mod tests {
         type Rep = u32;
         const PERIOD: Period = <Period>::new(1, 1_000);
 
-        fn now(&mut self) -> Instant<Self> {
+        fn now(&self) -> Instant<Self> {
             unimplemented!()
         }
     }

src/lib.rs

@@ -46,7 +46,7 @@
 //!     type Rep = u64;
 //!     const PERIOD: Period = <Period>::new(1, 16_000_000);
 //!
-//!     fn now(&mut self) -> Instant<Self> {
+//!     fn now(&self) -> Instant<Self> {
 //!         // ...
 //! #         unimplemented!()
 //!     }
@@ -122,7 +122,7 @@ mod tests {
         type Rep = u64;
         const PERIOD: time::Period = <time::Period>::new(1, 64_000_000);
 
-        fn now(&mut self) -> time::Instant<Self> {
+        fn now(&self) -> time::Instant<Self> {
             time::Instant::new(128_000_000)
         }
     }
@@ -134,7 +134,7 @@ mod tests {
         type Rep = u32;
         const PERIOD: time::Period = <time::Period>::new(1, 16_000_000);
 
-        fn now(&mut self) -> time::Instant<Self> {
+        fn now(&self) -> time::Instant<Self> {
             time::Instant::new(32_000_000)
         }
     }