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    //! Replaces the deprecated functionality of std::os::num_cpus.
    #![cfg_attr(test, deny(warnings))]
    #![deny(missing_docs)]
    #![allow(non_snake_case)]

    #[cfg(not(windows))]
    extern crate libc;

    /// Returns the number of CPUs of the current machine.
    #[inline]
    pub fn get() -> usize {
        get_num_cpus()
    }

    #[cfg(windows)]
    fn get_num_cpus() -> usize {
        #[repr(C)]
        struct SYSTEM_INFO {
            wProcessorArchitecture: u16,
            wReserved: u16,
            dwPageSize: u32,
            lpMinimumApplicationAddress: *mut u8,
            lpMaximumApplicationAddress: *mut u8,
            dwActiveProcessorMask: *mut u8,
            dwNumberOfProcessors: u32,
            dwProcessorType: u32,
            dwAllocationGranularity: u32,
            wProcessorLevel: u16,
            wProcessorRevision: u16,
        }

        extern "system" {
            fn GetSystemInfo(lpSystemInfo: *mut SYSTEM_INFO);
        }

        unsafe {
            let mut sysinfo: SYSTEM_INFO = std::mem::uninitialized();
            GetSystemInfo(&mut sysinfo);
            sysinfo.dwNumberOfProcessors as usize
        }
    }

    #[cfg(any(target_os = "freebsd",
              target_os = "dragonfly",
              target_os = "bitrig",
              target_os = "netbsd"))]
    fn get_num_cpus() -> usize {
        let mut cpus: libc::c_uint = 0;
        let mut cpus_size = std::mem::size_of_val(&cpus);

        unsafe {
            cpus = libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as libc::c_uint;
        }
        if cpus < 1 {
            let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];
            unsafe {
                libc::sysctl(mib.as_mut_ptr(),
                             2,
                             &mut cpus as *mut _ as *mut _,
                             &mut cpus_size as *mut _ as *mut _,
                             0 as *mut _,
                             0);
            }
            if cpus < 1 {
                cpus = 1;
            }
        }
        cpus as usize
    }

    #[cfg(target_os = "openbsd")]
    fn get_num_cpus() -> usize {
        let mut cpus: libc::c_uint = 0;
        let mut cpus_size = std::mem::size_of_val(&cpus);
        let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];

        unsafe {
            libc::sysctl(mib.as_mut_ptr(),
                         2,
                         &mut cpus as *mut _ as *mut _,
                         &mut cpus_size as *mut _ as *mut _,
                         0 as *mut _,
                         0);
        }
        if cpus < 1 {
            cpus = 1;
        }
        cpus as usize
    }

    #[cfg(
        any(
            target_os = "linux",
            target_os = "nacl",
            target_os = "macos",
            target_os = "ios",
            target_os = "android",
        )
    )]
    fn get_num_cpus() -> usize {
        unsafe {
            libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as usize
        }
    }

    #[test]
    fn lower_bound() {
        assert!(get() > 0);
    }

    #[test]
    fn upper_bound() {
        assert!(get() < 236_451);
    }

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