128 lines
3.2 KiB
Rust
128 lines
3.2 KiB
Rust
use core::num::Wrapping;
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use core::{f32, f64};
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#[cfg(has_i128)]
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use core::{i128, u128};
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use core::{i16, i32, i64, i8, isize};
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use core::{u16, u32, u64, u8, usize};
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/// Numbers which have upper and lower bounds
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pub trait Bounded {
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// FIXME (#5527): These should be associated constants
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/// returns the smallest finite number this type can represent
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fn min_value() -> Self;
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/// returns the largest finite number this type can represent
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fn max_value() -> Self;
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}
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macro_rules! bounded_impl {
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($t:ty, $min:expr, $max:expr) => {
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impl Bounded for $t {
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#[inline]
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fn min_value() -> $t {
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$min
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}
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#[inline]
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fn max_value() -> $t {
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$max
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}
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}
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};
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}
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bounded_impl!(usize, usize::MIN, usize::MAX);
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bounded_impl!(u8, u8::MIN, u8::MAX);
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bounded_impl!(u16, u16::MIN, u16::MAX);
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bounded_impl!(u32, u32::MIN, u32::MAX);
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bounded_impl!(u64, u64::MIN, u64::MAX);
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#[cfg(has_i128)]
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bounded_impl!(u128, u128::MIN, u128::MAX);
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bounded_impl!(isize, isize::MIN, isize::MAX);
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bounded_impl!(i8, i8::MIN, i8::MAX);
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bounded_impl!(i16, i16::MIN, i16::MAX);
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bounded_impl!(i32, i32::MIN, i32::MAX);
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bounded_impl!(i64, i64::MIN, i64::MAX);
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#[cfg(has_i128)]
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bounded_impl!(i128, i128::MIN, i128::MAX);
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impl<T: Bounded> Bounded for Wrapping<T> {
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fn min_value() -> Self {
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Wrapping(T::min_value())
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}
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fn max_value() -> Self {
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Wrapping(T::max_value())
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}
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}
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bounded_impl!(f32, f32::MIN, f32::MAX);
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macro_rules! for_each_tuple_ {
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( $m:ident !! ) => (
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$m! { }
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);
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( $m:ident !! $h:ident, $($t:ident,)* ) => (
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$m! { $h $($t)* }
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for_each_tuple_! { $m !! $($t,)* }
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);
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}
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macro_rules! for_each_tuple {
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($m:ident) => {
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for_each_tuple_! { $m !! A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, }
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};
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}
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macro_rules! bounded_tuple {
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( $($name:ident)* ) => (
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impl<$($name: Bounded,)*> Bounded for ($($name,)*) {
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#[inline]
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fn min_value() -> Self {
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($($name::min_value(),)*)
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}
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#[inline]
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fn max_value() -> Self {
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($($name::max_value(),)*)
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}
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}
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);
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}
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for_each_tuple!(bounded_tuple);
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bounded_impl!(f64, f64::MIN, f64::MAX);
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#[test]
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fn wrapping_bounded() {
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macro_rules! test_wrapping_bounded {
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($($t:ty)+) => {
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$(
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assert_eq!(Wrapping::<$t>::min_value().0, <$t>::min_value());
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assert_eq!(Wrapping::<$t>::max_value().0, <$t>::max_value());
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)+
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};
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}
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test_wrapping_bounded!(usize u8 u16 u32 u64 isize i8 i16 i32 i64);
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}
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#[cfg(has_i128)]
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#[test]
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fn wrapping_bounded_i128() {
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macro_rules! test_wrapping_bounded {
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($($t:ty)+) => {
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$(
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assert_eq!(Wrapping::<$t>::min_value().0, <$t>::min_value());
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assert_eq!(Wrapping::<$t>::max_value().0, <$t>::max_value());
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)+
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};
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}
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test_wrapping_bounded!(u128 i128);
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}
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#[test]
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fn wrapping_is_bounded() {
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fn require_bounded<T: Bounded>(_: &T) {}
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require_bounded(&Wrapping(42_u32));
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require_bounded(&Wrapping(-42));
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}
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