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use integer::Integer;
use malachite_base::num::basic::traits::Zero;
use malachite_base::num::conversion::traits::{CheckedFrom, ConvertibleFrom, SaturatingFrom};
use natural::Natural;
impl CheckedFrom<Integer> for Natural {
/// Converts an [`Integer`] to a [`Natural`], taking the [`Natural`] by value. If the
/// [`Integer`] is negative, `None` is returned.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// extern crate malachite_base;
///
/// use malachite_base::num::arithmetic::traits::Pow;
/// use malachite_base::num::conversion::traits::CheckedFrom;
/// use malachite_base::strings::ToDebugString;
/// use malachite_nz::integer::Integer;
/// use malachite_nz::natural::Natural;
///
/// assert_eq!(Natural::checked_from(Integer::from(123)).to_debug_string(), "Some(123)");
/// assert_eq!(Natural::checked_from(Integer::from(-123)).to_debug_string(), "None");
/// assert_eq!(
/// Natural::checked_from(Integer::from(10u32).pow(12)).to_debug_string(),
/// "Some(1000000000000)"
/// );
/// assert_eq!(Natural::checked_from(-Integer::from(10u32).pow(12)).to_debug_string(), "None");
/// ```
fn checked_from(value: Integer) -> Option<Natural> {
match value {
Integer { sign: false, .. } => None,
Integer { sign: true, abs } => Some(abs),
}
}
}
impl<'a> CheckedFrom<&'a Integer> for Natural {
/// Converts an [`Integer`] to a [`Natural`], taking the [`Natural`] by reference. If the
/// [`Integer`] is negative, `None` is returned.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `value.significant_bits()`.
///
/// # Examples
/// ```
/// extern crate malachite_base;
///
/// use malachite_base::num::arithmetic::traits::Pow;
/// use malachite_base::num::conversion::traits::CheckedFrom;
/// use malachite_base::strings::ToDebugString;
/// use malachite_nz::integer::Integer;
/// use malachite_nz::natural::Natural;
///
/// assert_eq!(Natural::checked_from(&Integer::from(123)).to_debug_string(), "Some(123)");
/// assert_eq!(Natural::checked_from(&Integer::from(-123)).to_debug_string(), "None");
/// assert_eq!(
/// Natural::checked_from(&Integer::from(10u32).pow(12)).to_debug_string(),
/// "Some(1000000000000)"
/// );
/// assert_eq!(
/// Natural::checked_from(&(-Integer::from(10u32).pow(12))).to_debug_string(),
/// "None"
/// );
/// ```
fn checked_from(value: &'a Integer) -> Option<Natural> {
match *value {
Integer { sign: false, .. } => None,
Integer {
sign: true,
ref abs,
} => Some(abs.clone()),
}
}
}
impl SaturatingFrom<Integer> for Natural {
/// Converts an [`Integer`] to a [`Natural`], taking the [`Natural`] by value. If the
/// [`Integer`] is negative, 0 is returned.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// extern crate malachite_base;
///
/// use malachite_base::num::arithmetic::traits::Pow;
/// use malachite_base::num::conversion::traits::SaturatingFrom;
/// use malachite_nz::integer::Integer;
/// use malachite_nz::natural::Natural;
///
/// assert_eq!(Natural::saturating_from(Integer::from(123)), 123);
/// assert_eq!(Natural::saturating_from(Integer::from(-123)), 0);
/// assert_eq!(Natural::saturating_from(Integer::from(10u32).pow(12)), 1000000000000u64);
/// assert_eq!(Natural::saturating_from(-Integer::from(10u32).pow(12)), 0);
/// ```
fn saturating_from(value: Integer) -> Natural {
match value {
Integer { sign: false, .. } => Natural::ZERO,
Integer { sign: true, abs } => abs,
}
}
}
impl<'a> SaturatingFrom<&'a Integer> for Natural {
/// Converts an [`Integer`] to a [`Natural`], taking the [`Natural`] by reference. If the
/// [`Integer`] is negative, 0 is returned.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// extern crate malachite_base;
///
/// use malachite_base::num::arithmetic::traits::Pow;
/// use malachite_base::num::conversion::traits::SaturatingFrom;
/// use malachite_nz::integer::Integer;
/// use malachite_nz::natural::Natural;
///
/// assert_eq!(Natural::saturating_from(&Integer::from(123)), 123);
/// assert_eq!(Natural::saturating_from(&Integer::from(-123)), 0);
/// assert_eq!(Natural::saturating_from(&Integer::from(10u32).pow(12)), 1000000000000u64);
/// assert_eq!(Natural::saturating_from(&-Integer::from(10u32).pow(12)), 0);
/// ```
fn saturating_from(value: &'a Integer) -> Natural {
match *value {
Integer { sign: false, .. } => Natural::ZERO,
Integer {
sign: true,
ref abs,
} => abs.clone(),
}
}
}
impl ConvertibleFrom<Integer> for Natural {
/// Determines whether an [`Integer`] can be converted to a [`Natural`] (when the [`Integer`]
/// is non-negative). Takes the [`Integer`] by value.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// extern crate malachite_base;
///
/// use malachite_base::num::arithmetic::traits::Pow;
/// use malachite_base::num::conversion::traits::ConvertibleFrom;
/// use malachite_nz::integer::Integer;
/// use malachite_nz::natural::Natural;
///
/// assert_eq!(Natural::convertible_from(Integer::from(123)), true);
/// assert_eq!(Natural::convertible_from(Integer::from(-123)), false);
/// assert_eq!(Natural::convertible_from(Integer::from(10u32).pow(12)), true);
/// assert_eq!(Natural::convertible_from(-Integer::from(10u32).pow(12)), false);
/// ```
#[inline]
fn convertible_from(value: Integer) -> bool {
value.sign
}
}
impl<'a> ConvertibleFrom<&'a Integer> for Natural {
/// Determines whether an [`Integer`] can be converted to a [`Natural`] (when the [`Integer`]
/// is non-negative). Takes the [`Integer`] by reference.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// extern crate malachite_base;
///
/// use malachite_base::num::arithmetic::traits::Pow;
/// use malachite_base::num::conversion::traits::ConvertibleFrom;
/// use malachite_nz::integer::Integer;
/// use malachite_nz::natural::Natural;
///
/// assert_eq!(Natural::convertible_from(&Integer::from(123)), true);
/// assert_eq!(Natural::convertible_from(&Integer::from(-123)), false);
/// assert_eq!(Natural::convertible_from(&Integer::from(10u32).pow(12)), true);
/// assert_eq!(Natural::convertible_from(&-Integer::from(10u32).pow(12)), false);
/// ```
#[inline]
fn convertible_from(value: &'a Integer) -> bool {
value.sign
}
}