embedded_hal/blocking/rng.rs
//! Blocking hardware random number generator
/// Blocking read
///
/// *This trait is available if embedded-hal is built with the `"unproven"` feature.*
#[cfg(feature = "unproven")]
pub trait Read {
/// Error type
type Error;
/// Reads enough bytes from hardware random number generator to fill `buffer`
///
/// If any error is encountered then this function immediately returns. The contents of buf are
/// unspecified in this case.
///
/// If this function returns an error, it is unspecified how many bytes it has read, but it
/// will never read more than would be necessary to completely fill the buffer.
fn read(&mut self, buffer: &mut [u8]) -> Result<(), Self::Error>;
}