/rust/registry/src/index.crates.io-1949cf8c6b5b557f/time-0.3.44/src/instant.rs

Source
//! The [`Instant`] struct and its associated `impl`s.

#![expect(deprecated)]

use core::borrow::Borrow;
use core::cmp::{Ord, Ordering, PartialEq, PartialOrd};
use core::ops::{Add, Sub};
use core::time::Duration as StdDuration;
use std::time::Instant as StdInstant;

use crate::internal_macros::{impl_add_assign, impl_sub_assign};
use crate::Duration;

/// A measurement of a monotonically non-decreasing clock. Opaque and useful only with [`Duration`].
///
/// Instants are always guaranteed to be no less than any previously measured instant when created,
/// and are often useful for tasks such as measuring benchmarks or timing how long an operation
/// takes.
///
/// Note, however, that instants are not guaranteed to be **steady**. In other words, each tick of
/// the underlying clock may not be the same length (e.g. some seconds may be longer than others).
/// An instant may jump forwards or experience time dilation (slow down or speed up), but it will
/// never go backwards.
///
/// Instants are opaque types that can only be compared to one another. There is no method to get
/// "the number of seconds" from an instant. Instead, it only allows measuring the duration between
/// two instants (or comparing two instants).
///
/// This implementation allows for operations with signed [`Duration`]s, but is otherwise identical
/// to [`std::time::Instant`].
#[doc(hidden)]
#[deprecated(
    since = "0.3.35",
    note = "import `std::time::Instant` and `time::ext::InstantExt` instead"
)]
#[repr(transparent)]
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Instant(pub StdInstant);

impl Instant {
    /// Returns an `Instant` corresponding to "now".
    ///
    /// ```rust
    /// # #![expect(deprecated)]
    /// # use time::Instant;
    /// println!("{:?}", Instant::now());
    /// ```
    #[inline]
    pub fn now() -> Self {
        Self(StdInstant::now())
    }

    /// Returns the amount of time elapsed since this instant was created. The duration will always
    /// be nonnegative if the instant is not synthetically created.
    ///
    /// ```rust
    /// # #![expect(deprecated)]
    /// # use time::{Instant, ext::{NumericalStdDuration, NumericalDuration}};
    /// # use std::thread;
    /// let instant = Instant::now();
    /// thread::sleep(1.std_milliseconds());
    /// assert!(instant.elapsed() >= 1.milliseconds());
    /// ```
    #[inline]
    pub fn elapsed(self) -> Duration {
        Self::now() - self
    }

    /// Returns `Some(t)` where `t` is the time `self + duration` if `t` can be represented as
    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
    /// otherwise.
    ///
    /// ```rust
    /// # #![expect(deprecated)]
    /// # use time::{Instant, ext::NumericalDuration};
    /// let now = Instant::now();
    /// assert_eq!(now.checked_add(5.seconds()), Some(now + 5.seconds()));
    /// assert_eq!(now.checked_add((-5).seconds()), Some(now + (-5).seconds()));
    /// ```
    #[inline]
    pub fn checked_add(self, duration: Duration) -> Option<Self> {
        if duration.is_zero() {
            Some(self)
        } else if duration.is_positive() {
            self.0.checked_add(duration.unsigned_abs()).map(Self)
        } else {
            debug_assert!(duration.is_negative());
            self.0.checked_sub(duration.unsigned_abs()).map(Self)
        }
    }

    /// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as
    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
    /// otherwise.
    ///
    /// ```rust
    /// # #![expect(deprecated)]
    /// # use time::{Instant, ext::NumericalDuration};
    /// let now = Instant::now();
    /// assert_eq!(now.checked_sub(5.seconds()), Some(now - 5.seconds()));
    /// assert_eq!(now.checked_sub((-5).seconds()), Some(now - (-5).seconds()));
    /// ```
    #[inline]
    pub fn checked_sub(self, duration: Duration) -> Option<Self> {
        if duration.is_zero() {
            Some(self)
        } else if duration.is_positive() {
            self.0.checked_sub(duration.unsigned_abs()).map(Self)
        } else {
            debug_assert!(duration.is_negative());
            self.0.checked_add(duration.unsigned_abs()).map(Self)
        }
    }

    /// Obtain the inner [`std::time::Instant`].
    ///
    /// ```rust
    /// # #![expect(deprecated)]
    /// # use time::Instant;
    /// let now = Instant::now();
    /// assert_eq!(now.into_inner(), now.0);
    /// ```
    #[inline]
    pub const fn into_inner(self) -> StdInstant {
        self.0
    }
}

impl From<StdInstant> for Instant {
    #[inline]
    fn from(instant: StdInstant) -> Self {
        Self(instant)
    }
}

impl From<Instant> for StdInstant {
    #[inline]
    fn from(instant: Instant) -> Self {
        instant.0
    }
}

impl Sub for Instant {
    type Output = Duration;

    /// # Panics
    ///
    /// This may panic if an overflow occurs.
    #[inline]
    fn sub(self, other: Self) -> Self::Output {
        match self.0.cmp(&other.0) {
            Ordering::Equal => Duration::ZERO,
            Ordering::Greater => (self.0 - other.0)
                .try_into()
                .expect("overflow converting `std::time::Duration` to `time::Duration`"),
            Ordering::Less => -Duration::try_from(other.0 - self.0)
                .expect("overflow converting `std::time::Duration` to `time::Duration`"),
        }
    }
}

impl Sub<StdInstant> for Instant {
    type Output = Duration;

    #[inline]
    fn sub(self, other: StdInstant) -> Self::Output {
        self - Self(other)
    }
}

impl Sub<Instant> for StdInstant {
    type Output = Duration;

    #[inline]
    fn sub(self, other: Instant) -> Self::Output {
        Instant(self) - other
    }
}

impl Add<Duration> for Instant {
    type Output = Self;

    /// # Panics
    ///
    /// This function may panic if the resulting point in time cannot be represented by the
    /// underlying data structure.
    #[inline]
    fn add(self, duration: Duration) -> Self::Output {
        if duration.is_positive() {
            Self(self.0 + duration.unsigned_abs())
        } else if duration.is_negative() {
            #[expect(clippy::unchecked_duration_subtraction)]
            Self(self.0 - duration.unsigned_abs())
        } else {
            debug_assert!(duration.is_zero());
            self
        }
    }
}

impl Add<Duration> for StdInstant {
    type Output = Self;

    #[inline]
    fn add(self, duration: Duration) -> Self::Output {
        (Instant(self) + duration).0
    }
}

impl Add<StdDuration> for Instant {
    type Output = Self;

    #[inline]
    fn add(self, duration: StdDuration) -> Self::Output {
        Self(self.0 + duration)
    }
}

impl_add_assign!(Instant: Duration, StdDuration);
impl_add_assign!(StdInstant: Duration);

impl Sub<Duration> for Instant {
    type Output = Self;

    /// # Panics
    ///
    /// This function may panic if the resulting point in time cannot be represented by the
    /// underlying data structure.
    #[inline]
    fn sub(self, duration: Duration) -> Self::Output {
        if duration.is_positive() {
            #[expect(clippy::unchecked_duration_subtraction)]
            Self(self.0 - duration.unsigned_abs())
        } else if duration.is_negative() {
            Self(self.0 + duration.unsigned_abs())
        } else {
            debug_assert!(duration.is_zero());
            self
        }
    }
}

impl Sub<Duration> for StdInstant {
    type Output = Self;

    #[inline]
    fn sub(self, duration: Duration) -> Self::Output {
        (Instant(self) - duration).0
    }
}

impl Sub<StdDuration> for Instant {
    type Output = Self;

    /// # Panics
    ///
    /// This function may panic if the resulting point in time cannot be represented by the
    /// underlying data structure.
    #[inline]
    fn sub(self, duration: StdDuration) -> Self::Output {
        #[expect(clippy::unchecked_duration_subtraction)]
        Self(self.0 - duration)
    }
}

impl_sub_assign!(Instant: Duration, StdDuration);
impl_sub_assign!(StdInstant: Duration);

impl PartialEq<StdInstant> for Instant {
    #[inline]
    fn eq(&self, rhs: &StdInstant) -> bool {
        self.0.eq(rhs)
    }
}

impl PartialEq<Instant> for StdInstant {
    #[inline]
    fn eq(&self, rhs: &Instant) -> bool {
        self.eq(&rhs.0)
    }
}

impl PartialOrd<StdInstant> for Instant {
    #[inline]
    fn partial_cmp(&self, rhs: &StdInstant) -> Option<Ordering> {
        self.0.partial_cmp(rhs)
    }
}

impl PartialOrd<Instant> for StdInstant {
    #[inline]
    fn partial_cmp(&self, rhs: &Instant) -> Option<Ordering> {
        self.partial_cmp(&rhs.0)
    }
}

impl AsRef<StdInstant> for Instant {
    #[inline]
    fn as_ref(&self) -> &StdInstant {
        &self.0
    }
}

impl Borrow<StdInstant> for Instant {
    #[inline]
    fn borrow(&self) -> &StdInstant {
        &self.0
    }
}

Coverage Report

Created: 2025-12-20 06:45

Line	Count	Source
1		//! The [`Instant`] struct and its associated `impl`s.
2
3		#![expect(deprecated)]
4
5		use core::borrow::Borrow;
6		use core::cmp::{Ord, Ordering, PartialEq, PartialOrd};
7		use core::ops::{Add, Sub};
8		use core::time::Duration as StdDuration;
9		use std::time::Instant as StdInstant;
10
11		use crate::internal_macros::{impl_add_assign, impl_sub_assign};
12		use crate::Duration;
13
14		/// A measurement of a monotonically non-decreasing clock. Opaque and useful only with [`Duration`].
15		///
16		/// Instants are always guaranteed to be no less than any previously measured instant when created,
17		/// and are often useful for tasks such as measuring benchmarks or timing how long an operation
18		/// takes.
19		///
20		/// Note, however, that instants are not guaranteed to be steady. In other words, each tick of
21		/// the underlying clock may not be the same length (e.g. some seconds may be longer than others).
22		/// An instant may jump forwards or experience time dilation (slow down or speed up), but it will
23		/// never go backwards.
24		///
25		/// Instants are opaque types that can only be compared to one another. There is no method to get
26		/// "the number of seconds" from an instant. Instead, it only allows measuring the duration between
27		/// two instants (or comparing two instants).
28		///
29		/// This implementation allows for operations with signed [`Duration`]s, but is otherwise identical
30		/// to [`std::time::Instant`].
31		#[doc(hidden)]
32		#[deprecated(
33		since = "0.3.35",
34		note = "import `std::time::Instant` and `time::ext::InstantExt` instead"
35		)]
36		#[repr(transparent)]
37		#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
38		pub struct Instant(pub StdInstant);
39
40		impl Instant {
41		/// Returns an `Instant` corresponding to "now".
42		///
43		/// ```rust
44		/// # #![expect(deprecated)]
45		/// # use time::Instant;
46		/// println!("{:?}", Instant::now());
47		/// ```
48		#[inline]
49	0	pub fn now() -> Self {
50	0	Self(StdInstant::now())
51	0	}
52
53		/// Returns the amount of time elapsed since this instant was created. The duration will always
54		/// be nonnegative if the instant is not synthetically created.
55		///
56		/// ```rust
57		/// # #![expect(deprecated)]
58		/// # use time::{Instant, ext::{NumericalStdDuration, NumericalDuration}};
59		/// # use std::thread;
60		/// let instant = Instant::now();
61		/// thread::sleep(1.std_milliseconds());
62		/// assert!(instant.elapsed() >= 1.milliseconds());
63		/// ```
64		#[inline]
65	0	pub fn elapsed(self) -> Duration {
66	0	Self::now() - self
67	0	}
68
69		/// Returns `Some(t)` where `t` is the time `self + duration` if `t` can be represented as
70		/// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
71		/// otherwise.
72		///
73		/// ```rust
74		/// # #![expect(deprecated)]
75		/// # use time::{Instant, ext::NumericalDuration};
76		/// let now = Instant::now();
77		/// assert_eq!(now.checked_add(5.seconds()), Some(now + 5.seconds()));
78		/// assert_eq!(now.checked_add((-5).seconds()), Some(now + (-5).seconds()));
79		/// ```
80		#[inline]
81	0	pub fn checked_add(self, duration: Duration) -> Option<Self> {
82	0	if duration.is_zero() {
83	0	Some(self)
84	0	} else if duration.is_positive() {
85	0	self.0.checked_add(duration.unsigned_abs()).map(Self)
86		} else {
87	0	debug_assert!(duration.is_negative());
88	0	self.0.checked_sub(duration.unsigned_abs()).map(Self)
89		}
90	0	}
91
92		/// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as
93		/// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
94		/// otherwise.
95		///
96		/// ```rust
97		/// # #![expect(deprecated)]
98		/// # use time::{Instant, ext::NumericalDuration};
99		/// let now = Instant::now();
100		/// assert_eq!(now.checked_sub(5.seconds()), Some(now - 5.seconds()));
101		/// assert_eq!(now.checked_sub((-5).seconds()), Some(now - (-5).seconds()));
102		/// ```
103		#[inline]
104	0	pub fn checked_sub(self, duration: Duration) -> Option<Self> {
105	0	if duration.is_zero() {
106	0	Some(self)
107	0	} else if duration.is_positive() {
108	0	self.0.checked_sub(duration.unsigned_abs()).map(Self)
109		} else {
110	0	debug_assert!(duration.is_negative());
111	0	self.0.checked_add(duration.unsigned_abs()).map(Self)
112		}
113	0	}
114
115		/// Obtain the inner [`std::time::Instant`].
116		///
117		/// ```rust
118		/// # #![expect(deprecated)]
119		/// # use time::Instant;
120		/// let now = Instant::now();
121		/// assert_eq!(now.into_inner(), now.0);
122		/// ```
123		#[inline]
124	0	pub const fn into_inner(self) -> StdInstant {
125	0	self.0
126	0	}
127		}
128
129		impl From<StdInstant> for Instant {
130		#[inline]
131	0	fn from(instant: StdInstant) -> Self {
132	0	Self(instant)
133	0	}
134		}
135
136		impl From<Instant> for StdInstant {
137		#[inline]
138	0	fn from(instant: Instant) -> Self {
139	0	instant.0
140	0	}
141		}
142
143		impl Sub for Instant {
144		type Output = Duration;
145
146		/// # Panics
147		///
148		/// This may panic if an overflow occurs.
149		#[inline]
150	0	fn sub(self, other: Self) -> Self::Output {
151	0	match self.0.cmp(&other.0) {
152	0	Ordering::Equal => Duration::ZERO,
153	0	Ordering::Greater => (self.0 - other.0)
154	0	.try_into()
155	0	.expect("overflow converting `std::time::Duration` to `time::Duration`"),
156	0	Ordering::Less => -Duration::try_from(other.0 - self.0)
157	0	.expect("overflow converting `std::time::Duration` to `time::Duration`"),
158		}
159	0	}
160		}
161
162		impl Sub<StdInstant> for Instant {
163		type Output = Duration;
164
165		#[inline]
166	0	fn sub(self, other: StdInstant) -> Self::Output {
167	0	self - Self(other)
168	0	}
169		}
170
171		impl Sub<Instant> for StdInstant {
172		type Output = Duration;
173
174		#[inline]
175	0	fn sub(self, other: Instant) -> Self::Output {
176	0	Instant(self) - other
177	0	}
178		}
179
180		impl Add<Duration> for Instant {
181		type Output = Self;
182
183		/// # Panics
184		///
185		/// This function may panic if the resulting point in time cannot be represented by the
186		/// underlying data structure.
187		#[inline]
188	0	fn add(self, duration: Duration) -> Self::Output {
189	0	if duration.is_positive() {
190	0	Self(self.0 + duration.unsigned_abs())
191	0	} else if duration.is_negative() {
192		#[expect(clippy::unchecked_duration_subtraction)]
193	0	Self(self.0 - duration.unsigned_abs())
194		} else {
195	0	debug_assert!(duration.is_zero());
196	0	self
197		}
198	0	}
199		}
200
201		impl Add<Duration> for StdInstant {
202		type Output = Self;
203
204		#[inline]
205	0	fn add(self, duration: Duration) -> Self::Output {
206	0	(Instant(self) + duration).0
207	0	}
208		}
209
210		impl Add<StdDuration> for Instant {
211		type Output = Self;
212
213		#[inline]
214	0	fn add(self, duration: StdDuration) -> Self::Output {
215	0	Self(self.0 + duration)
216	0	}
217		}
218
219		impl_add_assign!(Instant: Duration, StdDuration);
220		impl_add_assign!(StdInstant: Duration);
221
222		impl Sub<Duration> for Instant {
223		type Output = Self;
224
225		/// # Panics
226		///
227		/// This function may panic if the resulting point in time cannot be represented by the
228		/// underlying data structure.
229		#[inline]
230	0	fn sub(self, duration: Duration) -> Self::Output {
231	0	if duration.is_positive() {
232		#[expect(clippy::unchecked_duration_subtraction)]
233	0	Self(self.0 - duration.unsigned_abs())
234	0	} else if duration.is_negative() {
235	0	Self(self.0 + duration.unsigned_abs())
236		} else {
237	0	debug_assert!(duration.is_zero());
238	0	self
239		}
240	0	}
241		}
242
243		impl Sub<Duration> for StdInstant {
244		type Output = Self;
245
246		#[inline]
247	0	fn sub(self, duration: Duration) -> Self::Output {
248	0	(Instant(self) - duration).0
249	0	}
250		}
251
252		impl Sub<StdDuration> for Instant {
253		type Output = Self;
254
255		/// # Panics
256		///
257		/// This function may panic if the resulting point in time cannot be represented by the
258		/// underlying data structure.
259		#[inline]
260	0	fn sub(self, duration: StdDuration) -> Self::Output {
261		#[expect(clippy::unchecked_duration_subtraction)]
262	0	Self(self.0 - duration)
263	0	}
264		}
265
266		impl_sub_assign!(Instant: Duration, StdDuration);
267		impl_sub_assign!(StdInstant: Duration);
268
269		impl PartialEq<StdInstant> for Instant {
270		#[inline]
271	0	fn eq(&self, rhs: &StdInstant) -> bool {
272	0	self.0.eq(rhs)
273	0	}
274		}
275
276		impl PartialEq<Instant> for StdInstant {
277		#[inline]
278	0	fn eq(&self, rhs: &Instant) -> bool {
279	0	self.eq(&rhs.0)
280	0	}
281		}
282
283		impl PartialOrd<StdInstant> for Instant {
284		#[inline]
285	0	fn partial_cmp(&self, rhs: &StdInstant) -> Option<Ordering> {
286	0	self.0.partial_cmp(rhs)
287	0	}
288		}
289
290		impl PartialOrd<Instant> for StdInstant {
291		#[inline]
292	0	fn partial_cmp(&self, rhs: &Instant) -> Option<Ordering> {
293	0	self.partial_cmp(&rhs.0)
294	0	}
295		}
296
297		impl AsRef<StdInstant> for Instant {
298		#[inline]
299	0	fn as_ref(&self) -> &StdInstant {
300	0	&self.0
301	0	}
302		}
303
304		impl Borrow<StdInstant> for Instant {
305		#[inline]
306	0	fn borrow(&self) -> &StdInstant {
307	0	&self.0
308	0	}
309		}