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impl 128-bit numeric casts 

This includes new conditional methods `ToPrimitive::{to_i128,to_u128}`
and `FromPrimitive::{from_i128,from_u128}`.  Since features can only be
additive, these methods must not cause a breaking change to anyone when
enabled -- thus they have a default implementation that converts through
64-bit values.  Types that can do better with a full 128-bit integer,
like bigint or floating-point, will probably want to override these.
This commit is contained in:
Josh Stone 2018-05-07 12:28:53 -07:00
parent 6161f1ade1
commit bbbc2bd1d7
2 changed files with 508 additions and 289 deletions
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478
src/cast.rs
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@ -3,6 +3,8 @@ use core::{u8, u16, u32, u64, usize};
use core::{f32, f64}; use core::{f32, f64};
use core::mem::size_of; use core::mem::size_of;
use core::num::Wrapping; use core::num::Wrapping;
#[cfg(feature = "i128")]
use core::{i128, u128};
use float::FloatCore; use float::FloatCore;
@ -35,6 +37,18 @@ pub trait ToPrimitive {
/// Converts the value of `self` to an `i64`. /// Converts the value of `self` to an `i64`.
fn to_i64(&self) -> Option<i64>; fn to_i64(&self) -> Option<i64>;
/// Converts the value of `self` to an `i128`.
///
/// This method is only available with feature `i128` enabled on Rust >= 1.26.
///
/// The default implementation converts through `to_i64()`. Types implementing
/// this trait should override this method if they can represent a greater range.
#[inline]
#[cfg(feature = "i128")]
fn to_i128(&self) -> Option<i128> {
self.to_i64().map(From::from)
}
/// Converts the value of `self` to a `usize`. /// Converts the value of `self` to a `usize`.
#[inline] #[inline]
fn to_usize(&self) -> Option<usize> { fn to_usize(&self) -> Option<usize> {
@ -63,6 +77,18 @@ pub trait ToPrimitive {
#[inline] #[inline]
fn to_u64(&self) -> Option<u64>; fn to_u64(&self) -> Option<u64>;
/// Converts the value of `self` to an `u128`.
///
/// This method is only available with feature `i128` enabled on Rust >= 1.26.
///
/// The default implementation converts through `to_u64()`. Types implementing
/// this trait should override this method if they can represent a greater range.
#[inline]
#[cfg(feature = "i128")]
fn to_u128(&self) -> Option<u128> {
self.to_u64().map(From::from)
}
/// Converts the value of `self` to an `f32`. /// Converts the value of `self` to an `f32`.
#[inline] #[inline]
fn to_f32(&self) -> Option<f32> { fn to_f32(&self) -> Option<f32> {
@ -77,8 +103,9 @@ pub trait ToPrimitive {
} }
macro_rules! impl_to_primitive_int_to_int { macro_rules! impl_to_primitive_int_to_int {
($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( ($SrcT:ident : $( $(#[$cfg:meta])* fn $method:ident -> $DstT:ident ; )*) => {$(
#[inline] #[inline]
$(#[$cfg])*
fn $method(&self) -> Option<$DstT> { fn $method(&self) -> Option<$DstT> {
let min = $DstT::MIN as $SrcT; let min = $DstT::MIN as $SrcT;
let max = $DstT::MAX as $SrcT; let max = $DstT::MAX as $SrcT;
@ -92,11 +119,12 @@ macro_rules! impl_to_primitive_int_to_int {
} }
macro_rules! impl_to_primitive_int_to_uint { macro_rules! impl_to_primitive_int_to_uint {
($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( ($SrcT:ident : $( $(#[$cfg:meta])* fn $method:ident -> $DstT:ident ; )*) => {$(
#[inline] #[inline]
$(#[$cfg])*
fn $method(&self) -> Option<$DstT> { fn $method(&self) -> Option<$DstT> {
let max = $DstT::MAX as u64; let max = $DstT::MAX as $SrcT;
if 0 <= *self && (size_of::<$SrcT>() < size_of::<$DstT>() || *self as u64 <= max) { if 0 <= *self && (size_of::<$SrcT>() <= size_of::<$DstT>() || *self <= max) {
Some(*self as $DstT) Some(*self as $DstT)
} else { } else {
None None
@ -114,6 +142,8 @@ macro_rules! impl_to_primitive_int {
fn to_i16 -> i16; fn to_i16 -> i16;
fn to_i32 -> i32; fn to_i32 -> i32;
fn to_i64 -> i64; fn to_i64 -> i64;
#[cfg(feature = "i128")]
fn to_i128 -> i128;
} }
impl_to_primitive_int_to_uint! { $T: impl_to_primitive_int_to_uint! { $T:
@ -122,6 +152,8 @@ macro_rules! impl_to_primitive_int {
fn to_u16 -> u16; fn to_u16 -> u16;
fn to_u32 -> u32; fn to_u32 -> u32;
fn to_u64 -> u64; fn to_u64 -> u64;
#[cfg(feature = "i128")]
fn to_u128 -> u128;
} }
#[inline] #[inline]
@ -137,13 +169,16 @@ impl_to_primitive_int!(i8);
impl_to_primitive_int!(i16); impl_to_primitive_int!(i16);
impl_to_primitive_int!(i32); impl_to_primitive_int!(i32);
impl_to_primitive_int!(i64); impl_to_primitive_int!(i64);
#[cfg(feature = "i128")]
impl_to_primitive_int!(i128);
macro_rules! impl_to_primitive_uint_to_int { macro_rules! impl_to_primitive_uint_to_int {
($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( ($SrcT:ident : $( $(#[$cfg:meta])* fn $method:ident -> $DstT:ident ; )*) => {$(
#[inline] #[inline]
$(#[$cfg])*
fn $method(&self) -> Option<$DstT> { fn $method(&self) -> Option<$DstT> {
let max = $DstT::MAX as u64; let max = $DstT::MAX as $SrcT;
if size_of::<$SrcT>() < size_of::<$DstT>() || *self as u64 <= max { if size_of::<$SrcT>() < size_of::<$DstT>() || *self <= max {
Some(*self as $DstT) Some(*self as $DstT)
} else { } else {
None None
@ -153,8 +188,9 @@ macro_rules! impl_to_primitive_uint_to_int {
} }
macro_rules! impl_to_primitive_uint_to_uint { macro_rules! impl_to_primitive_uint_to_uint {
($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( ($SrcT:ident : $( $(#[$cfg:meta])* fn $method:ident -> $DstT:ident ; )*) => {$(
#[inline] #[inline]
$(#[$cfg])*
fn $method(&self) -> Option<$DstT> { fn $method(&self) -> Option<$DstT> {
let max = $DstT::MAX as $SrcT; let max = $DstT::MAX as $SrcT;
if size_of::<$SrcT>() <= size_of::<$DstT>() || *self <= max { if size_of::<$SrcT>() <= size_of::<$DstT>() || *self <= max {
@ -175,6 +211,8 @@ macro_rules! impl_to_primitive_uint {
fn to_i16 -> i16; fn to_i16 -> i16;
fn to_i32 -> i32; fn to_i32 -> i32;
fn to_i64 -> i64; fn to_i64 -> i64;
#[cfg(feature = "i128")]
fn to_i128 -> i128;
} }
impl_to_primitive_uint_to_uint! { $T: impl_to_primitive_uint_to_uint! { $T:
@ -183,6 +221,8 @@ macro_rules! impl_to_primitive_uint {
fn to_u16 -> u16; fn to_u16 -> u16;
fn to_u32 -> u32; fn to_u32 -> u32;
fn to_u64 -> u64; fn to_u64 -> u64;
#[cfg(feature = "i128")]
fn to_u128 -> u128;
} }
#[inline] #[inline]
@ -198,6 +238,8 @@ impl_to_primitive_uint!(u8);
impl_to_primitive_uint!(u16); impl_to_primitive_uint!(u16);
impl_to_primitive_uint!(u32); impl_to_primitive_uint!(u32);
impl_to_primitive_uint!(u64); impl_to_primitive_uint!(u64);
#[cfg(feature = "i128")]
impl_to_primitive_uint!(u128);
macro_rules! impl_to_primitive_float_to_float { macro_rules! impl_to_primitive_float_to_float {
($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( ($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$(
@ -217,8 +259,9 @@ macro_rules! impl_to_primitive_float_to_float {
} }
macro_rules! impl_to_primitive_float_to_signed_int { macro_rules! impl_to_primitive_float_to_signed_int {
($f:ident : $( fn $method:ident -> $i:ident ; )*) => {$( ($f:ident : $( $(#[$cfg:meta])* fn $method:ident -> $i:ident ; )*) => {$(
#[inline] #[inline]
$(#[$cfg])*
fn $method(&self) -> Option<$i> { fn $method(&self) -> Option<$i> {
// Float as int truncates toward zero, so we want to allow values // Float as int truncates toward zero, so we want to allow values
// in the exclusive range `(MIN-1, MAX+1)`. // in the exclusive range `(MIN-1, MAX+1)`.
@ -246,8 +289,9 @@ macro_rules! impl_to_primitive_float_to_signed_int {
} }
macro_rules! impl_to_primitive_float_to_unsigned_int { macro_rules! impl_to_primitive_float_to_unsigned_int {
($f:ident : $( fn $method:ident -> $u:ident ; )*) => {$( ($f:ident : $( $(#[$cfg:meta])* fn $method:ident -> $u:ident ; )*) => {$(
#[inline] #[inline]
$(#[$cfg])*
fn $method(&self) -> Option<$u> { fn $method(&self) -> Option<$u> {
// Float as int truncates toward zero, so we want to allow values // Float as int truncates toward zero, so we want to allow values
// in the exclusive range `(-1, MAX+1)`. // in the exclusive range `(-1, MAX+1)`.
@ -260,6 +304,7 @@ macro_rules! impl_to_primitive_float_to_unsigned_int {
} else { } else {
// We can't represent `MAX` exactly, but it will round up to exactly // We can't represent `MAX` exactly, but it will round up to exactly
// `MAX+1` (a power of two) when we cast it. // `MAX+1` (a power of two) when we cast it.
// (`u128::MAX as f32` is infinity, but this is still ok.)
const MAX_P1: $f = $u::MAX as $f; const MAX_P1: $f = $u::MAX as $f;
if *self > -1.0 && *self < MAX_P1 { if *self > -1.0 && *self < MAX_P1 {
return Some(*self as $u); return Some(*self as $u);
@ -279,6 +324,8 @@ macro_rules! impl_to_primitive_float {
fn to_i16 -> i16; fn to_i16 -> i16;
fn to_i32 -> i32; fn to_i32 -> i32;
fn to_i64 -> i64; fn to_i64 -> i64;
#[cfg(feature = "i128")]
fn to_i128 -> i128;
} }
impl_to_primitive_float_to_unsigned_int! { $T: impl_to_primitive_float_to_unsigned_int! { $T:
@ -287,6 +334,8 @@ macro_rules! impl_to_primitive_float {
fn to_u16 -> u16; fn to_u16 -> u16;
fn to_u32 -> u32; fn to_u32 -> u32;
fn to_u64 -> u64; fn to_u64 -> u64;
#[cfg(feature = "i128")]
fn to_u128 -> u128;
} }
impl_to_primitive_float_to_float! { $T: impl_to_primitive_float_to_float! { $T:
@ -334,6 +383,19 @@ pub trait FromPrimitive: Sized {
/// type cannot be represented by this value, the `None` is returned. /// type cannot be represented by this value, the `None` is returned.
fn from_i64(n: i64) -> Option<Self>; fn from_i64(n: i64) -> Option<Self>;
/// Convert an `i128` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
///
/// This method is only available with feature `i128` enabled on Rust >= 1.26.
///
/// The default implementation converts through `from_i64()`. Types implementing
/// this trait should override this method if they can represent a greater range.
#[inline]
#[cfg(feature = "i128")]
fn from_i128(n: i128) -> Option<Self> {
n.to_i64().and_then(FromPrimitive::from_i64)
}
/// Convert a `usize` to return an optional value of this type. If the /// Convert a `usize` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned. /// type cannot be represented by this value, the `None` is returned.
#[inline] #[inline]
@ -366,6 +428,19 @@ pub trait FromPrimitive: Sized {
/// type cannot be represented by this value, the `None` is returned. /// type cannot be represented by this value, the `None` is returned.
fn from_u64(n: u64) -> Option<Self>; fn from_u64(n: u64) -> Option<Self>;
/// Convert an `u128` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
///
/// This method is only available with feature `i128` enabled on Rust >= 1.26.
///
/// The default implementation converts through `from_u64()`. Types implementing
/// this trait should override this method if they can represent a greater range.
#[inline]
#[cfg(feature = "i128")]
fn from_u128(n: u128) -> Option<Self> {
n.to_u64().and_then(FromPrimitive::from_u64)
}
/// Convert a `f32` to return an optional value of this type. If the /// Convert a `f32` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned. /// type cannot be represented by this value, the `None` is returned.
#[inline] #[inline]
@ -389,11 +464,15 @@ macro_rules! impl_from_primitive {
#[inline] fn from_i16(n: i16) -> Option<$T> { n.$to_ty() } #[inline] fn from_i16(n: i16) -> Option<$T> { n.$to_ty() }
#[inline] fn from_i32(n: i32) -> Option<$T> { n.$to_ty() } #[inline] fn from_i32(n: i32) -> Option<$T> { n.$to_ty() }
#[inline] fn from_i64(n: i64) -> Option<$T> { n.$to_ty() } #[inline] fn from_i64(n: i64) -> Option<$T> { n.$to_ty() }
#[cfg(feature = "i128")]
#[inline] fn from_i128(n: i128) -> Option<$T> { n.$to_ty() }
#[inline] fn from_u8(n: u8) -> Option<$T> { n.$to_ty() } #[inline] fn from_u8(n: u8) -> Option<$T> { n.$to_ty() }
#[inline] fn from_u16(n: u16) -> Option<$T> { n.$to_ty() } #[inline] fn from_u16(n: u16) -> Option<$T> { n.$to_ty() }
#[inline] fn from_u32(n: u32) -> Option<$T> { n.$to_ty() } #[inline] fn from_u32(n: u32) -> Option<$T> { n.$to_ty() }
#[inline] fn from_u64(n: u64) -> Option<$T> { n.$to_ty() } #[inline] fn from_u64(n: u64) -> Option<$T> { n.$to_ty() }
#[cfg(feature = "i128")]
#[inline] fn from_u128(n: u128) -> Option<$T> { n.$to_ty() }
#[inline] fn from_f32(n: f32) -> Option<$T> { n.$to_ty() } #[inline] fn from_f32(n: f32) -> Option<$T> { n.$to_ty() }
#[inline] fn from_f64(n: f64) -> Option<$T> { n.$to_ty() } #[inline] fn from_f64(n: f64) -> Option<$T> { n.$to_ty() }
@ -406,22 +485,83 @@ impl_from_primitive!(i8, to_i8);
impl_from_primitive!(i16, to_i16); impl_from_primitive!(i16, to_i16);
impl_from_primitive!(i32, to_i32); impl_from_primitive!(i32, to_i32);
impl_from_primitive!(i64, to_i64); impl_from_primitive!(i64, to_i64);
#[cfg(feature = "i128")]
impl_from_primitive!(i128, to_i128);
impl_from_primitive!(usize, to_usize); impl_from_primitive!(usize, to_usize);
impl_from_primitive!(u8, to_u8); impl_from_primitive!(u8, to_u8);
impl_from_primitive!(u16, to_u16); impl_from_primitive!(u16, to_u16);
impl_from_primitive!(u32, to_u32); impl_from_primitive!(u32, to_u32);
impl_from_primitive!(u64, to_u64); impl_from_primitive!(u64, to_u64);
#[cfg(feature = "i128")]
impl_from_primitive!(u128, to_u128);
impl_from_primitive!(f32, to_f32); impl_from_primitive!(f32, to_f32);
impl_from_primitive!(f64, to_f64); impl_from_primitive!(f64, to_f64);
impl<T: ToPrimitive> ToPrimitive for Wrapping<T> { macro_rules! impl_to_primitive_wrapping {
fn to_i64(&self) -> Option<i64> { self.0.to_i64() } ($( $(#[$cfg:meta])* fn $method:ident -> $i:ident ; )*) => {$(
fn to_u64(&self) -> Option<u64> { self.0.to_u64() } #[inline]
$(#[$cfg])*
fn $method(&self) -> Option<$i> {
(self.0).$method()
}
)*}
} }
impl<T: ToPrimitive> ToPrimitive for Wrapping<T> {
impl_to_primitive_wrapping! {
fn to_isize -> isize;
fn to_i8 -> i8;
fn to_i16 -> i16;
fn to_i32 -> i32;
fn to_i64 -> i64;
#[cfg(feature = "i128")]
fn to_i128 -> i128;
fn to_usize -> usize;
fn to_u8 -> u8;
fn to_u16 -> u16;
fn to_u32 -> u32;
fn to_u64 -> u64;
#[cfg(feature = "i128")]
fn to_u128 -> u128;
fn to_f32 -> f32;
fn to_f64 -> f64;
}
}
macro_rules! impl_from_primitive_wrapping {
($( $(#[$cfg:meta])* fn $method:ident ( $i:ident ); )*) => {$(
#[inline]
$(#[$cfg])*
fn $method(n: $i) -> Option<Self> {
T::$method(n).map(Wrapping)
}
)*}
}
impl<T: FromPrimitive> FromPrimitive for Wrapping<T> { impl<T: FromPrimitive> FromPrimitive for Wrapping<T> {
fn from_u64(n: u64) -> Option<Self> { T::from_u64(n).map(Wrapping) } impl_from_primitive_wrapping! {
fn from_i64(n: i64) -> Option<Self> { T::from_i64(n).map(Wrapping) } fn from_isize(isize);
fn from_i8(i8);
fn from_i16(i16);
fn from_i32(i32);
fn from_i64(i64);
#[cfg(feature = "i128")]
fn from_i128(i128);
fn from_usize(usize);
fn from_u8(u8);
fn from_u16(u16);
fn from_u32(u32);
fn from_u64(u64);
#[cfg(feature = "i128")]
fn from_u128(u128);
fn from_f32(f32);
fn from_f64(f64);
}
} }
@ -465,11 +605,15 @@ impl_num_cast!(u8, to_u8);
impl_num_cast!(u16, to_u16); impl_num_cast!(u16, to_u16);
impl_num_cast!(u32, to_u32); impl_num_cast!(u32, to_u32);
impl_num_cast!(u64, to_u64); impl_num_cast!(u64, to_u64);
#[cfg(feature = "i128")]
impl_num_cast!(u128, to_u128);
impl_num_cast!(usize, to_usize); impl_num_cast!(usize, to_usize);
impl_num_cast!(i8, to_i8); impl_num_cast!(i8, to_i8);
impl_num_cast!(i16, to_i16); impl_num_cast!(i16, to_i16);
impl_num_cast!(i32, to_i32); impl_num_cast!(i32, to_i32);
impl_num_cast!(i64, to_i64); impl_num_cast!(i64, to_i64);
#[cfg(feature = "i128")]
impl_num_cast!(i128, to_i128);
impl_num_cast!(isize, to_isize); impl_num_cast!(isize, to_isize);
impl_num_cast!(f32, to_f32); impl_num_cast!(f32, to_f32);
impl_num_cast!(f64, to_f64); impl_num_cast!(f64, to_f64);
@ -524,284 +668,40 @@ where
} }
macro_rules! impl_as_primitive { macro_rules! impl_as_primitive {
($T: ty => $( $U: ty ),* ) => { (@ $T: ty => $(#[$cfg:meta])* impl $U: ty ) => {
$( $(#[$cfg])*
impl AsPrimitive<$U> for $T { impl AsPrimitive<$U> for $T {
#[inline] fn as_(self) -> $U { self as $U } #[inline] fn as_(self) -> $U { self as $U }
} }
)* };
(@ $T: ty => { $( $U: ty ),* } ) => {$(
impl_as_primitive!(@ $T => impl $U);
)*};
($T: ty => { $( $U: ty ),* } ) => {
impl_as_primitive!(@ $T => { $( $U ),* });
impl_as_primitive!(@ $T => { u8, u16, u32, u64, usize });
impl_as_primitive!(@ $T => #[cfg(feature = "i128")] impl u128);
impl_as_primitive!(@ $T => { i8, i16, i32, i64, isize });
impl_as_primitive!(@ $T => #[cfg(feature = "i128")] impl i128);
}; };
} }
impl_as_primitive!(u8 => char, u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(u8 => { char, f32, f64 });
impl_as_primitive!(i8 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(i8 => { f32, f64 });
impl_as_primitive!(u16 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(u16 => { f32, f64 });
impl_as_primitive!(i16 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(i16 => { f32, f64 });
impl_as_primitive!(u32 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(u32 => { f32, f64 });
impl_as_primitive!(i32 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(i32 => { f32, f64 });
impl_as_primitive!(u64 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(u64 => { f32, f64 });
impl_as_primitive!(i64 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(i64 => { f32, f64 });
impl_as_primitive!(usize => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); #[cfg(feature = "i128")]
impl_as_primitive!(isize => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(u128 => { f32, f64 });
impl_as_primitive!(f32 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); #[cfg(feature = "i128")]
impl_as_primitive!(f64 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64); impl_as_primitive!(i128 => { f32, f64 });
impl_as_primitive!(char => char, u8, i8, u16, i16, u32, i32, u64, isize, usize, i64); impl_as_primitive!(usize => { f32, f64 });
impl_as_primitive!(bool => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64); impl_as_primitive!(isize => { f32, f64 });
impl_as_primitive!(f32 => { f32, f64 });
impl_as_primitive!(f64 => { f32, f64 });
impl_as_primitive!(char => { char });
impl_as_primitive!(bool => {});
#[test]
fn to_primitive_float() {
use core::f32;
use core::f64;
let f32_toolarge = 1e39f64;
assert_eq!(f32_toolarge.to_f32(), None);
assert_eq!((f32::MAX as f64).to_f32(), Some(f32::MAX));
assert_eq!((-f32::MAX as f64).to_f32(), Some(-f32::MAX));
assert_eq!(f64::INFINITY.to_f32(), Some(f32::INFINITY));
assert_eq!((f64::NEG_INFINITY).to_f32(), Some(f32::NEG_INFINITY));
assert!((f64::NAN).to_f32().map_or(false, |f| f.is_nan()));
}
#[test]
fn wrapping_to_primitive() {
macro_rules! test_wrapping_to_primitive {
($($t:ty)+) => {
$({
let i: $t = 0;
let w = Wrapping(i);
assert_eq!(i.to_u8(), w.to_u8());
assert_eq!(i.to_u16(), w.to_u16());
assert_eq!(i.to_u32(), w.to_u32());
assert_eq!(i.to_u64(), w.to_u64());
assert_eq!(i.to_usize(), w.to_usize());
assert_eq!(i.to_i8(), w.to_i8());
assert_eq!(i.to_i16(), w.to_i16());
assert_eq!(i.to_i32(), w.to_i32());
assert_eq!(i.to_i64(), w.to_i64());
assert_eq!(i.to_isize(), w.to_isize());
assert_eq!(i.to_f32(), w.to_f32());
assert_eq!(i.to_f64(), w.to_f64());
})+
};
}
test_wrapping_to_primitive!(usize u8 u16 u32 u64 isize i8 i16 i32 i64);
}
#[test]
fn wrapping_is_toprimitive() {
fn require_toprimitive<T: ToPrimitive>(_: &T) {}
require_toprimitive(&Wrapping(42));
}
#[test]
fn wrapping_is_fromprimitive() {
fn require_fromprimitive<T: FromPrimitive>(_: &T) {}
require_fromprimitive(&Wrapping(42));
}
#[test]
fn wrapping_is_numcast() {
fn require_numcast<T: NumCast>(_: &T) {}
require_numcast(&Wrapping(42));
}
#[test]
fn as_primitive() {
let x: f32 = (1.625f64).as_();
assert_eq!(x, 1.625f32);
let x: f32 = (3.14159265358979323846f64).as_();
assert_eq!(x, 3.1415927f32);
let x: u8 = (768i16).as_();
assert_eq!(x, 0);
}
#[test]
fn float_to_integer_checks_overflow() {
// This will overflow an i32
let source: f64 = 1.0e+123f64;
// Expect the overflow to be caught
assert_eq!(cast::<f64, i32>(source), None);
}
#[test]
fn cast_to_int_checks_overflow() {
let big_f: f64 = 1.0e123;
let normal_f: f64 = 1.0;
let small_f: f64 = -1.0e123;
assert_eq!(None, cast::<f64, isize>(big_f));
assert_eq!(None, cast::<f64, i8>(big_f));
assert_eq!(None, cast::<f64, i16>(big_f));
assert_eq!(None, cast::<f64, i32>(big_f));
assert_eq!(None, cast::<f64, i64>(big_f));
assert_eq!(Some(normal_f as isize), cast::<f64, isize>(normal_f));
assert_eq!(Some(normal_f as i8), cast::<f64, i8>(normal_f));
assert_eq!(Some(normal_f as i16), cast::<f64, i16>(normal_f));
assert_eq!(Some(normal_f as i32), cast::<f64, i32>(normal_f));
assert_eq!(Some(normal_f as i64), cast::<f64, i64>(normal_f));
assert_eq!(None, cast::<f64, isize>(small_f));
assert_eq!(None, cast::<f64, i8>(small_f));
assert_eq!(None, cast::<f64, i16>(small_f));
assert_eq!(None, cast::<f64, i32>(small_f));
assert_eq!(None, cast::<f64, i64>(small_f));
}
#[test]
fn cast_to_unsigned_int_checks_overflow() {
let big_f: f64 = 1.0e123;
let normal_f: f64 = 1.0;
let small_f: f64 = -1.0e123;
assert_eq!(None, cast::<f64, usize>(big_f));
assert_eq!(None, cast::<f64, u8>(big_f));
assert_eq!(None, cast::<f64, u16>(big_f));
assert_eq!(None, cast::<f64, u32>(big_f));
assert_eq!(None, cast::<f64, u64>(big_f));
assert_eq!(Some(normal_f as usize), cast::<f64, usize>(normal_f));
assert_eq!(Some(normal_f as u8), cast::<f64, u8>(normal_f));
assert_eq!(Some(normal_f as u16), cast::<f64, u16>(normal_f));
assert_eq!(Some(normal_f as u32), cast::<f64, u32>(normal_f));
assert_eq!(Some(normal_f as u64), cast::<f64, u64>(normal_f));
assert_eq!(None, cast::<f64, usize>(small_f));
assert_eq!(None, cast::<f64, u8>(small_f));
assert_eq!(None, cast::<f64, u16>(small_f));
assert_eq!(None, cast::<f64, u32>(small_f));
assert_eq!(None, cast::<f64, u64>(small_f));
}
#[cfg(all(test, feature = "std"))]
fn dbg(args: ::core::fmt::Arguments) {
println!("{}", args);
}
#[cfg(all(test, not(feature = "std")))]
fn dbg(_: ::core::fmt::Arguments) {}
// Rust 1.8 doesn't handle cfg on macros correctly
// #[cfg(test)]
#[allow(unused)]
macro_rules! dbg { ($($tok:tt)*) => { dbg(format_args!($($tok)*)) } }
#[test]
fn cast_float_to_int_edge_cases() {
use core::mem::transmute;
trait RawOffset: Sized {
type Raw;
fn raw_offset(self, offset: Self::Raw) -> Self;
}
impl RawOffset for f32 {
type Raw = i32;
fn raw_offset(self, offset: Self::Raw) -> Self {
unsafe {
let raw: Self::Raw = transmute(self);
transmute(raw + offset)
}
}
}
impl RawOffset for f64 {
type Raw = i64;
fn raw_offset(self, offset: Self::Raw) -> Self {
unsafe {
let raw: Self::Raw = transmute(self);
transmute(raw + offset)
}
}
}
macro_rules! test_edge {
($f:ident -> $($t:ident)+) => { $({
dbg!("testing cast edge cases for {} -> {}", stringify!($f), stringify!($t));
let small = if $t::MIN == 0 || size_of::<$t>() < size_of::<$f>() {
$t::MIN as $f - 1.0
} else {
($t::MIN as $f).raw_offset(1).floor()
};
let fmin = small.raw_offset(-1);
dbg!(" testing min {}\n\tvs. {:.16}\n\tand {:.16}", $t::MIN, fmin, small);
assert_eq!(Some($t::MIN), cast::<$f, $t>($t::MIN as $f));
assert_eq!(Some($t::MIN), cast::<$f, $t>(fmin));
assert_eq!(None, cast::<$f, $t>(small));
let (max, large) = if size_of::<$t>() < size_of::<$f>() {
($t::MAX, $t::MAX as $f + 1.0)
} else {
let large = $t::MAX as $f; // rounds up!
let max = large.raw_offset(-1) as $t; // the next smallest possible
assert_eq!(max.count_ones(), $f::MANTISSA_DIGITS);
(max, large)
};
let fmax = large.raw_offset(-1);
dbg!(" testing max {}\n\tvs. {:.16}\n\tand {:.16}", max, fmax, large);
assert_eq!(Some(max), cast::<$f, $t>(max as $f));
assert_eq!(Some(max), cast::<$f, $t>(fmax));
assert_eq!(None, cast::<$f, $t>(large));
dbg!(" testing non-finite values");
assert_eq!(None, cast::<$f, $t>($f::NAN));
assert_eq!(None, cast::<$f, $t>($f::INFINITY));
assert_eq!(None, cast::<$f, $t>($f::NEG_INFINITY));
})+}
}
test_edge!(f32 -> isize i8 i16 i32 i64);
test_edge!(f32 -> usize u8 u16 u32 u64);
test_edge!(f64 -> isize i8 i16 i32 i64);
test_edge!(f64 -> usize u8 u16 u32 u64);
}
#[test]
fn cast_int_to_int_edge_cases() {
use core::cmp::Ordering::*;
macro_rules! test_edge {
($f:ident -> $($t:ident)+) => { $({
fn test_edge() {
dbg!("testing cast edge cases for {} -> {}", stringify!($f), stringify!($t));
match ($f::MIN as i64).cmp(&($t::MIN as i64)) {
Greater => {
assert_eq!(Some($f::MIN as $t), cast::<$f, $t>($f::MIN));
}
Equal => {
assert_eq!(Some($t::MIN), cast::<$f, $t>($f::MIN));
}
Less => {
let min = $t::MIN as $f;
assert_eq!(Some($t::MIN), cast::<$f, $t>(min));
assert_eq!(None, cast::<$f, $t>(min - 1));
}
}
match ($f::MAX as u64).cmp(&($t::MAX as u64)) {
Greater => {
let max = $t::MAX as $f;
assert_eq!(Some($t::MAX), cast::<$f, $t>(max));
assert_eq!(None, cast::<$f, $t>(max + 1));
}
Equal => {
assert_eq!(Some($t::MAX), cast::<$f, $t>($f::MAX));
}
Less => {
assert_eq!(Some($f::MAX as $t), cast::<$f, $t>($f::MAX));
}
}
}
test_edge();
})+};
($( $from:ident )+) => { $({
test_edge!($from -> isize i8 i16 i32 i64);
test_edge!($from -> usize u8 u16 u32 u64);
})+}
}
test_edge!(isize i8 i16 i32 i64);
test_edge!(usize u8 u16 u32 u64);
}

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//! Tests of `num_traits::cast`.
#![no_std]
#[cfg(feature = "std")]
#[macro_use]
extern crate std;
extern crate num_traits;
use num_traits::cast::*;
use core::{i8, i16, i32, i64, isize};
use core::{u8, u16, u32, u64, usize};
use core::{f32, f64};
#[cfg(feature = "i128")]
use core::{i128, u128};
use core::mem;
use core::num::Wrapping;
#[test]
fn to_primitive_float() {
let f32_toolarge = 1e39f64;
assert_eq!(f32_toolarge.to_f32(), None);
assert_eq!((f32::MAX as f64).to_f32(), Some(f32::MAX));
assert_eq!((-f32::MAX as f64).to_f32(), Some(-f32::MAX));
assert_eq!(f64::INFINITY.to_f32(), Some(f32::INFINITY));
assert_eq!((f64::NEG_INFINITY).to_f32(), Some(f32::NEG_INFINITY));
assert!((f64::NAN).to_f32().map_or(false, |f| f.is_nan()));
}
#[test]
fn wrapping_to_primitive() {
macro_rules! test_wrapping_to_primitive {
($($t:ty)+) => {
$({
let i: $t = 0;
let w = Wrapping(i);
assert_eq!(i.to_u8(), w.to_u8());
assert_eq!(i.to_u16(), w.to_u16());
assert_eq!(i.to_u32(), w.to_u32());
assert_eq!(i.to_u64(), w.to_u64());
assert_eq!(i.to_usize(), w.to_usize());
assert_eq!(i.to_i8(), w.to_i8());
assert_eq!(i.to_i16(), w.to_i16());
assert_eq!(i.to_i32(), w.to_i32());
assert_eq!(i.to_i64(), w.to_i64());
assert_eq!(i.to_isize(), w.to_isize());
assert_eq!(i.to_f32(), w.to_f32());
assert_eq!(i.to_f64(), w.to_f64());
})+
};
}
test_wrapping_to_primitive!(usize u8 u16 u32 u64 isize i8 i16 i32 i64);
}
#[test]
fn wrapping_is_toprimitive() {
fn require_toprimitive<T: ToPrimitive>(_: &T) {}
require_toprimitive(&Wrapping(42));
}
#[test]
fn wrapping_is_fromprimitive() {
fn require_fromprimitive<T: FromPrimitive>(_: &T) {}
require_fromprimitive(&Wrapping(42));
}
#[test]
fn wrapping_is_numcast() {
fn require_numcast<T: NumCast>(_: &T) {}
require_numcast(&Wrapping(42));
}
#[test]
fn as_primitive() {
let x: f32 = (1.625f64).as_();
assert_eq!(x, 1.625f32);
let x: f32 = (3.14159265358979323846f64).as_();
assert_eq!(x, 3.1415927f32);
let x: u8 = (768i16).as_();
assert_eq!(x, 0);
}
#[test]
fn float_to_integer_checks_overflow() {
// This will overflow an i32
let source: f64 = 1.0e+123f64;
// Expect the overflow to be caught
assert_eq!(cast::<f64, i32>(source), None);
}
#[test]
fn cast_to_int_checks_overflow() {
let big_f: f64 = 1.0e123;
let normal_f: f64 = 1.0;
let small_f: f64 = -1.0e123;
assert_eq!(None, cast::<f64, isize>(big_f));
assert_eq!(None, cast::<f64, i8>(big_f));
assert_eq!(None, cast::<f64, i16>(big_f));
assert_eq!(None, cast::<f64, i32>(big_f));
assert_eq!(None, cast::<f64, i64>(big_f));
assert_eq!(Some(normal_f as isize), cast::<f64, isize>(normal_f));
assert_eq!(Some(normal_f as i8), cast::<f64, i8>(normal_f));
assert_eq!(Some(normal_f as i16), cast::<f64, i16>(normal_f));
assert_eq!(Some(normal_f as i32), cast::<f64, i32>(normal_f));
assert_eq!(Some(normal_f as i64), cast::<f64, i64>(normal_f));
assert_eq!(None, cast::<f64, isize>(small_f));
assert_eq!(None, cast::<f64, i8>(small_f));
assert_eq!(None, cast::<f64, i16>(small_f));
assert_eq!(None, cast::<f64, i32>(small_f));
assert_eq!(None, cast::<f64, i64>(small_f));
}
#[test]
fn cast_to_unsigned_int_checks_overflow() {
let big_f: f64 = 1.0e123;
let normal_f: f64 = 1.0;
let small_f: f64 = -1.0e123;
assert_eq!(None, cast::<f64, usize>(big_f));
assert_eq!(None, cast::<f64, u8>(big_f));
assert_eq!(None, cast::<f64, u16>(big_f));
assert_eq!(None, cast::<f64, u32>(big_f));
assert_eq!(None, cast::<f64, u64>(big_f));
assert_eq!(Some(normal_f as usize), cast::<f64, usize>(normal_f));
assert_eq!(Some(normal_f as u8), cast::<f64, u8>(normal_f));
assert_eq!(Some(normal_f as u16), cast::<f64, u16>(normal_f));
assert_eq!(Some(normal_f as u32), cast::<f64, u32>(normal_f));
assert_eq!(Some(normal_f as u64), cast::<f64, u64>(normal_f));
assert_eq!(None, cast::<f64, usize>(small_f));
assert_eq!(None, cast::<f64, u8>(small_f));
assert_eq!(None, cast::<f64, u16>(small_f));
assert_eq!(None, cast::<f64, u32>(small_f));
assert_eq!(None, cast::<f64, u64>(small_f));
}
#[test]
#[cfg(feature = "i128")]
fn cast_to_i128_checks_overflow() {
let big_f: f64 = 1.0e123;
let normal_f: f64 = 1.0;
let small_f: f64 = -1.0e123;
assert_eq!(None, cast::<f64, i128>(big_f));
assert_eq!(None, cast::<f64, u128>(big_f));
assert_eq!(Some(normal_f as i128), cast::<f64, i128>(normal_f));
assert_eq!(Some(normal_f as u128), cast::<f64, u128>(normal_f));
assert_eq!(None, cast::<f64, i128>(small_f));
assert_eq!(None, cast::<f64, u128>(small_f));
}
#[cfg(feature = "std")]
fn dbg(args: ::core::fmt::Arguments) {
println!("{}", args);
}
#[cfg(not(feature = "std"))]
fn dbg(_: ::core::fmt::Arguments) {}
// Rust 1.8 doesn't handle cfg on macros correctly
macro_rules! dbg { ($($tok:tt)*) => { dbg(format_args!($($tok)*)) } }
macro_rules! float_test_edge {
($f:ident -> $($t:ident)+) => { $({
dbg!("testing cast edge cases for {} -> {}", stringify!($f), stringify!($t));
let small = if $t::MIN == 0 || mem::size_of::<$t>() < mem::size_of::<$f>() {
$t::MIN as $f - 1.0
} else {
($t::MIN as $f).raw_offset(1).floor()
};
let fmin = small.raw_offset(-1);
dbg!(" testing min {}\n\tvs. {:.0}\n\tand {:.0}", $t::MIN, fmin, small);
assert_eq!(Some($t::MIN), cast::<$f, $t>($t::MIN as $f));
assert_eq!(Some($t::MIN), cast::<$f, $t>(fmin));
assert_eq!(None, cast::<$f, $t>(small));
let (max, large) = if mem::size_of::<$t>() < mem::size_of::<$f>() {
($t::MAX, $t::MAX as $f + 1.0)
} else {
let large = $t::MAX as $f; // rounds up!
let max = large.raw_offset(-1) as $t; // the next smallest possible
assert_eq!(max.count_ones(), $f::MANTISSA_DIGITS);
(max, large)
};
let fmax = large.raw_offset(-1);
dbg!(" testing max {}\n\tvs. {:.0}\n\tand {:.0}", max, fmax, large);
assert_eq!(Some(max), cast::<$f, $t>(max as $f));
assert_eq!(Some(max), cast::<$f, $t>(fmax));
assert_eq!(None, cast::<$f, $t>(large));
dbg!(" testing non-finite values");
assert_eq!(None, cast::<$f, $t>($f::NAN));
assert_eq!(None, cast::<$f, $t>($f::INFINITY));
assert_eq!(None, cast::<$f, $t>($f::NEG_INFINITY));
})+}
}
trait RawOffset: Sized {
type Raw;
fn raw_offset(self, offset: Self::Raw) -> Self;
}
impl RawOffset for f32 {
type Raw = i32;
fn raw_offset(self, offset: Self::Raw) -> Self {
unsafe {
let raw: Self::Raw = mem::transmute(self);
mem::transmute(raw + offset)
}
}
}
impl RawOffset for f64 {
type Raw = i64;
fn raw_offset(self, offset: Self::Raw) -> Self {
unsafe {
let raw: Self::Raw = mem::transmute(self);
mem::transmute(raw + offset)
}
}
}
#[test]
fn cast_float_to_int_edge_cases() {
float_test_edge!(f32 -> isize i8 i16 i32 i64);
float_test_edge!(f32 -> usize u8 u16 u32 u64);
float_test_edge!(f64 -> isize i8 i16 i32 i64);
float_test_edge!(f64 -> usize u8 u16 u32 u64);
}
#[test]
#[cfg(feature = "i128")]
fn cast_float_to_i128_edge_cases() {
float_test_edge!(f32 -> i128 u128);
float_test_edge!(f64 -> i128 u128);
}
macro_rules! int_test_edge {
($f:ident -> { $($t:ident)+ } with $BigS:ident $BigU:ident ) => { $({
fn test_edge() {
dbg!("testing cast edge cases for {} -> {}", stringify!($f), stringify!($t));
match ($f::MIN as $BigS).cmp(&($t::MIN as $BigS)) {
Greater => {
assert_eq!(Some($f::MIN as $t), cast::<$f, $t>($f::MIN));
}
Equal => {
assert_eq!(Some($t::MIN), cast::<$f, $t>($f::MIN));
}
Less => {
let min = $t::MIN as $f;
assert_eq!(Some($t::MIN), cast::<$f, $t>(min));
assert_eq!(None, cast::<$f, $t>(min - 1));
}
}
match ($f::MAX as $BigU).cmp(&($t::MAX as $BigU)) {
Greater => {
let max = $t::MAX as $f;
assert_eq!(Some($t::MAX), cast::<$f, $t>(max));
assert_eq!(None, cast::<$f, $t>(max + 1));
}
Equal => {
assert_eq!(Some($t::MAX), cast::<$f, $t>($f::MAX));
}
Less => {
assert_eq!(Some($f::MAX as $t), cast::<$f, $t>($f::MAX));
}
}
}
test_edge();
})+}
}
#[test]
fn cast_int_to_int_edge_cases() {
use core::cmp::Ordering::*;
macro_rules! test_edge {
($( $from:ident )+) => { $({
int_test_edge!($from -> { isize i8 i16 i32 i64 } with i64 u64);
int_test_edge!($from -> { usize u8 u16 u32 u64 } with i64 u64);
})+}
}
test_edge!(isize i8 i16 i32 i64);
test_edge!(usize u8 u16 u32 u64);
}
#[test]
#[cfg(feature = "i128")]
fn cast_int_to_128_edge_cases() {
use core::cmp::Ordering::*;
macro_rules! test_edge {
($( $t:ident )+) => {
$(
int_test_edge!($t -> { i128 u128 } with i128 u128);
)+
int_test_edge!(i128 -> { $( $t )+ } with i128 u128);
int_test_edge!(u128 -> { $( $t )+ } with i128 u128);
}
}
test_edge!(isize i8 i16 i32 i64 i128);
test_edge!(usize u8 u16 u32 u64 u128);
}