Remove TIoPin from IoPin example

Author: Morgan Roff

src/digital.rs

@@ -177,23 +177,21 @@ pub trait InputPin {
 
 /// Single pin that can switch from input to output mode, and vice-versa.
 ///
-/// Example use (assumes the Error type is the same for IoPin, InputPin, and
-/// OutputPin):
+/// Example use (assumes the `Error` type is the same for `InputPin`, and
+/// `OutputPin`):
 ///
 /// ```
 /// use core::time::Duration;
-/// use embedded_hal::digital::{IoPin, InputPin, OutputPin, PinState};
+/// use embedded_hal::digital::{IoPin, InputPin, OutputPin};
 ///
-/// pub fn ping_and_read<TIoPin, TInputPin, TOutputPin, TError>(
-///     pin: TIoPin, delay_fn: &dyn Fn(Duration) -> ()) -> Result<bool, TError>
+/// pub fn ping_and_read<TInputPin, TOutputPin, TError>(
+///     mut pin: TOutputPin, delay_fn: &dyn Fn(Duration) -> ()) -> Result<bool, TError>
 /// where
-///     TIoPin : IoPin<TInputPin, TOutputPin, Error = TError>,
 ///     TInputPin : InputPin<Error = TError> + IoPin<TInputPin, TOutputPin, Error = TError>,
 ///     TOutputPin : OutputPin<Error = TError> + IoPin<TInputPin, TOutputPin, Error = TError>,
 /// {
-///
 ///     // Ping
-///     let mut pin = pin.try_into_output_pin(PinState::Low)?;
+///     pin.try_set_low()?;
 ///     delay_fn(Duration::from_millis(10));
 ///     pin.try_set_high()?;
 ///