proptest 0.9.3

Hypothesis-like property-based testing and shrinking.
// Copyright 2017, 2018 The proptest developers
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
//> or the MIT license
// <LICENSE-MIT or>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Arbitrary implementations for `std::time`.

use std::time::*;
use core::ops::Range;

use crate::strategy::statics::{self, static_map};
use crate::arbitrary::*;
use crate::num;

arbitrary!(Duration, SMapped<(u64, u32), Self>;
    static_map(any::<(u64, u32)>(), |(a, b)| Duration::new(a, b))

// Instant::now() "never" returns the same Instant, so no shrinking may occur!
arbitrary!(Instant; Self::now());

    // We can't use `any::<Duration>()` because the addition to `SystemTime`
    // can overflow and panic. To be conservative, we only allow seconds to go
    // to i32::MAX since a certain popular OS still uses `i32` to represent the
    // seconds counter.
    SystemTime, statics::Map<(num::i32::Any, Range<u32>),
                             fn ((i32, u32)) -> SystemTime>;
    static_map((num::i32::ANY, 0..1_000_000_000u32),
                |(sec, ns)| {
                    if sec >= 0 {
                        UNIX_EPOCH + Duration::new(sec as u64, ns)
                    } else {
                        UNIX_EPOCH - Duration::new((-(sec as i64)) as u64, ns)

mod test {
        duration => Duration,
        instant  => Instant,
        system_time => SystemTime