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use crate::time::{Duration, SystemTime, SystemTimeError};
use ambient_authority::AmbientAuthority;
use std::time;
/// A reference to a system clock, useful for talking to external entities like
/// the file system or other processes.
///
/// This does not directly correspond to anything in `std`, however its methods
/// correspond to [methods in `std::time::SystemTime`].
///
/// [methods in `std::time::SystemTime`]: https://doc.rust-lang.org/std/time/struct.SystemTime.html#impl
pub struct SystemClock(());
impl SystemClock {
/// An anchor in time which can be used to create new `SystemTime`
/// instances or learn about where in time a `SystemTime` lies.
///
/// This corresponds to [`std::time::SystemTime::UNIX_EPOCH`].
pub const UNIX_EPOCH: SystemTime = SystemTime {
std: time::SystemTime::UNIX_EPOCH,
};
/// Constructs a new instance of `Self`.
///
/// # Ambient Authority
///
/// This uses ambient authority to accesses clocks.
#[inline]
pub const fn new(ambient_authority: AmbientAuthority) -> Self {
let _ = ambient_authority;
Self(())
}
/// Returns an instant corresponding to "now".
///
/// This corresponds to [`std::time::SystemTime::now`].
#[inline]
pub fn now(&self) -> SystemTime {
SystemTime::from_std(time::SystemTime::now())
}
/// Returns the amount of time elapsed since this instant was created.
///
/// This corresponds to [`std::time::SystemTime::elapsed`].
#[inline]
pub fn elapsed(&self, system_time: SystemTime) -> Result<Duration, SystemTimeError> {
system_time.std.elapsed()
}
}