+use super::{From, TryFrom};
+use crate::num::TryFromIntError;
+
mod private {
/// This trait being unreachable from outside the crate
/// prevents other implementations of the `FloatToInt` trait,
impl_float_to_int!(f32 => u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize);
impl_float_to_int!(f64 => u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize);
+
+// Conversion traits for primitive integer and float types
+// Conversions T -> T are covered by a blanket impl and therefore excluded
+// Some conversions from and to usize/isize are not implemented due to portability concerns
+macro_rules! impl_from {
+ ($Small: ty, $Large: ty, #[$attr:meta], $doc: expr) => {
+ #[$attr]
+ #[doc = $doc]
+ impl From<$Small> for $Large {
+ #[inline]
+ fn from(small: $Small) -> $Large {
+ small as $Large
+ }
+ }
+ };
+ ($Small: ty, $Large: ty, #[$attr:meta]) => {
+ impl_from!($Small,
+ $Large,
+ #[$attr],
+ concat!("Converts `",
+ stringify!($Small),
+ "` to `",
+ stringify!($Large),
+ "` losslessly."));
+ }
+}
+
+macro_rules! impl_from_bool {
+ ($target: ty, #[$attr:meta]) => {
+ impl_from!(bool, $target, #[$attr], concat!("Converts a `bool` to a `",
+ stringify!($target), "`. The resulting value is `0` for `false` and `1` for `true`
+values.
+
+# Examples
+
+```
+assert_eq!(", stringify!($target), "::from(true), 1);
+assert_eq!(", stringify!($target), "::from(false), 0);
+```"));
+ };
+}
+
+// Bool -> Any
+impl_from_bool! { u8, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { u16, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { u32, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { u64, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { u128, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { usize, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { i8, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { i16, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { i32, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { i64, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { i128, #[stable(feature = "from_bool", since = "1.28.0")] }
+impl_from_bool! { isize, #[stable(feature = "from_bool", since = "1.28.0")] }
+
+// Unsigned -> Unsigned
+impl_from! { u8, u16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u8, u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u8, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u8, u128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { u8, usize, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u16, u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u16, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u16, u128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { u32, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u32, u128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { u64, u128, #[stable(feature = "i128", since = "1.26.0")] }
+
+// Signed -> Signed
+impl_from! { i8, i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { i8, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { i8, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { i8, i128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { i8, isize, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { i16, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { i16, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { i16, i128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { i32, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { i32, i128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { i64, i128, #[stable(feature = "i128", since = "1.26.0")] }
+
+// Unsigned -> Signed
+impl_from! { u8, i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u8, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u8, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u8, i128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { u16, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u16, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u16, i128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { u32, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
+impl_from! { u32, i128, #[stable(feature = "i128", since = "1.26.0")] }
+impl_from! { u64, i128, #[stable(feature = "i128", since = "1.26.0")] }
+
+// The C99 standard defines bounds on INTPTR_MIN, INTPTR_MAX, and UINTPTR_MAX
+// which imply that pointer-sized integers must be at least 16 bits:
+// https://port70.net/~nsz/c/c99/n1256.html#7.18.2.4
+impl_from! { u16, usize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
+impl_from! { u8, isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
+impl_from! { i16, isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
+
+// RISC-V defines the possibility of a 128-bit address space (RV128).
+
+// CHERI proposes 256-bit “capabilities”. Unclear if this would be relevant to usize/isize.
+// https://www.cl.cam.ac.uk/research/security/ctsrd/pdfs/20171017a-cheri-poster.pdf
+// http://www.csl.sri.com/users/neumann/2012resolve-cheri.pdf
+
+
+// Note: integers can only be represented with full precision in a float if
+// they fit in the significand, which is 24 bits in f32 and 53 bits in f64.
+// Lossy float conversions are not implemented at this time.
+
+// Signed -> Float
+impl_from! { i8, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+impl_from! { i8, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+impl_from! { i16, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+impl_from! { i16, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+impl_from! { i32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+
+// Unsigned -> Float
+impl_from! { u8, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+impl_from! { u8, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+impl_from! { u16, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+impl_from! { u16, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+impl_from! { u32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+
+// Float -> Float
+impl_from! { f32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
+
+// no possible bounds violation
+macro_rules! try_from_unbounded {
+ ($source:ty, $($target:ty),*) => {$(
+ #[stable(feature = "try_from", since = "1.34.0")]
+ impl TryFrom<$source> for $target {
+ type Error = TryFromIntError;
+
+ /// Try to create the target number type from a source
+ /// number type. This returns an error if the source value
+ /// is outside of the range of the target type.
+ #[inline]
+ fn try_from(value: $source) -> Result<Self, Self::Error> {
+ Ok(value as $target)
+ }
+ }
+ )*}
+}
+
+// only negative bounds
+macro_rules! try_from_lower_bounded {
+ ($source:ty, $($target:ty),*) => {$(
+ #[stable(feature = "try_from", since = "1.34.0")]
+ impl TryFrom<$source> for $target {
+ type Error = TryFromIntError;
+
+ /// Try to create the target number type from a source
+ /// number type. This returns an error if the source value
+ /// is outside of the range of the target type.
+ #[inline]
+ fn try_from(u: $source) -> Result<$target, TryFromIntError> {
+ if u >= 0 {
+ Ok(u as $target)
+ } else {
+ Err(TryFromIntError(()))
+ }
+ }
+ }
+ )*}
+}
+
+// unsigned to signed (only positive bound)
+macro_rules! try_from_upper_bounded {
+ ($source:ty, $($target:ty),*) => {$(
+ #[stable(feature = "try_from", since = "1.34.0")]
+ impl TryFrom<$source> for $target {
+ type Error = TryFromIntError;
+
+ /// Try to create the target number type from a source
+ /// number type. This returns an error if the source value
+ /// is outside of the range of the target type.
+ #[inline]
+ fn try_from(u: $source) -> Result<$target, TryFromIntError> {
+ if u > (<$target>::max_value() as $source) {
+ Err(TryFromIntError(()))
+ } else {
+ Ok(u as $target)
+ }
+ }
+ }
+ )*}
+}
+
+// all other cases
+macro_rules! try_from_both_bounded {
+ ($source:ty, $($target:ty),*) => {$(
+ #[stable(feature = "try_from", since = "1.34.0")]
+ impl TryFrom<$source> for $target {
+ type Error = TryFromIntError;
+
+ /// Try to create the target number type from a source
+ /// number type. This returns an error if the source value
+ /// is outside of the range of the target type.
+ #[inline]
+ fn try_from(u: $source) -> Result<$target, TryFromIntError> {
+ let min = <$target>::min_value() as $source;
+ let max = <$target>::max_value() as $source;
+ if u < min || u > max {
+ Err(TryFromIntError(()))
+ } else {
+ Ok(u as $target)
+ }
+ }
+ }
+ )*}
+}
+
+macro_rules! rev {
+ ($mac:ident, $source:ty, $($target:ty),*) => {$(
+ $mac!($target, $source);
+ )*}
+}
+
+// intra-sign conversions
+try_from_upper_bounded!(u16, u8);
+try_from_upper_bounded!(u32, u16, u8);
+try_from_upper_bounded!(u64, u32, u16, u8);
+try_from_upper_bounded!(u128, u64, u32, u16, u8);
+
+try_from_both_bounded!(i16, i8);
+try_from_both_bounded!(i32, i16, i8);
+try_from_both_bounded!(i64, i32, i16, i8);
+try_from_both_bounded!(i128, i64, i32, i16, i8);
+
+// unsigned-to-signed
+try_from_upper_bounded!(u8, i8);
+try_from_upper_bounded!(u16, i8, i16);
+try_from_upper_bounded!(u32, i8, i16, i32);
+try_from_upper_bounded!(u64, i8, i16, i32, i64);
+try_from_upper_bounded!(u128, i8, i16, i32, i64, i128);
+
+// signed-to-unsigned
+try_from_lower_bounded!(i8, u8, u16, u32, u64, u128);
+try_from_lower_bounded!(i16, u16, u32, u64, u128);
+try_from_lower_bounded!(i32, u32, u64, u128);
+try_from_lower_bounded!(i64, u64, u128);
+try_from_lower_bounded!(i128, u128);
+try_from_both_bounded!(i16, u8);
+try_from_both_bounded!(i32, u16, u8);
+try_from_both_bounded!(i64, u32, u16, u8);
+try_from_both_bounded!(i128, u64, u32, u16, u8);
+
+// usize/isize
+try_from_upper_bounded!(usize, isize);
+try_from_lower_bounded!(isize, usize);
+
+#[cfg(target_pointer_width = "16")]
+mod ptr_try_from_impls {
+ use super::TryFromIntError;
+ use crate::convert::TryFrom;
+
+ try_from_upper_bounded!(usize, u8);
+ try_from_unbounded!(usize, u16, u32, u64, u128);
+ try_from_upper_bounded!(usize, i8, i16);
+ try_from_unbounded!(usize, i32, i64, i128);
+
+ try_from_both_bounded!(isize, u8);
+ try_from_lower_bounded!(isize, u16, u32, u64, u128);
+ try_from_both_bounded!(isize, i8);
+ try_from_unbounded!(isize, i16, i32, i64, i128);
+
+ rev!(try_from_upper_bounded, usize, u32, u64, u128);
+ rev!(try_from_lower_bounded, usize, i8, i16);
+ rev!(try_from_both_bounded, usize, i32, i64, i128);
+
+ rev!(try_from_upper_bounded, isize, u16, u32, u64, u128);
+ rev!(try_from_both_bounded, isize, i32, i64, i128);
+}
+
+#[cfg(target_pointer_width = "32")]
+mod ptr_try_from_impls {
+ use super::TryFromIntError;
+ use crate::convert::TryFrom;
+
+ try_from_upper_bounded!(usize, u8, u16);
+ try_from_unbounded!(usize, u32, u64, u128);
+ try_from_upper_bounded!(usize, i8, i16, i32);
+ try_from_unbounded!(usize, i64, i128);
+
+ try_from_both_bounded!(isize, u8, u16);
+ try_from_lower_bounded!(isize, u32, u64, u128);
+ try_from_both_bounded!(isize, i8, i16);
+ try_from_unbounded!(isize, i32, i64, i128);
+
+ rev!(try_from_unbounded, usize, u32);
+ rev!(try_from_upper_bounded, usize, u64, u128);
+ rev!(try_from_lower_bounded, usize, i8, i16, i32);
+ rev!(try_from_both_bounded, usize, i64, i128);
+
+ rev!(try_from_unbounded, isize, u16);
+ rev!(try_from_upper_bounded, isize, u32, u64, u128);
+ rev!(try_from_unbounded, isize, i32);
+ rev!(try_from_both_bounded, isize, i64, i128);
+}
+
+#[cfg(target_pointer_width = "64")]
+mod ptr_try_from_impls {
+ use super::TryFromIntError;
+ use crate::convert::TryFrom;
+
+ try_from_upper_bounded!(usize, u8, u16, u32);
+ try_from_unbounded!(usize, u64, u128);
+ try_from_upper_bounded!(usize, i8, i16, i32, i64);
+ try_from_unbounded!(usize, i128);
+
+ try_from_both_bounded!(isize, u8, u16, u32);
+ try_from_lower_bounded!(isize, u64, u128);
+ try_from_both_bounded!(isize, i8, i16, i32);
+ try_from_unbounded!(isize, i64, i128);
+
+ rev!(try_from_unbounded, usize, u32, u64);
+ rev!(try_from_upper_bounded, usize, u128);
+ rev!(try_from_lower_bounded, usize, i8, i16, i32, i64);
+ rev!(try_from_both_bounded, usize, i128);
+
+ rev!(try_from_unbounded, isize, u16, u32);
+ rev!(try_from_upper_bounded, isize, u64, u128);
+ rev!(try_from_unbounded, isize, i32, i64);
+ rev!(try_from_both_bounded, isize, i128);
+}
#![stable(feature = "rust1", since = "1.0.0")]
-use crate::convert::TryFrom;
use crate::fmt;
use crate::intrinsics;
use crate::mem;
/// The error type returned when a checked integral type conversion fails.
#[stable(feature = "try_from", since = "1.34.0")]
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-pub struct TryFromIntError(());
+pub struct TryFromIntError(pub(crate) ());
impl TryFromIntError {
#[unstable(feature = "int_error_internals",
}
}
-// no possible bounds violation
-macro_rules! try_from_unbounded {
- ($source:ty, $($target:ty),*) => {$(
- #[stable(feature = "try_from", since = "1.34.0")]
- impl TryFrom<$source> for $target {
- type Error = TryFromIntError;
-
- /// Try to create the target number type from a source
- /// number type. This returns an error if the source value
- /// is outside of the range of the target type.
- #[inline]
- fn try_from(value: $source) -> Result<Self, Self::Error> {
- Ok(value as $target)
- }
- }
- )*}
-}
-
-// only negative bounds
-macro_rules! try_from_lower_bounded {
- ($source:ty, $($target:ty),*) => {$(
- #[stable(feature = "try_from", since = "1.34.0")]
- impl TryFrom<$source> for $target {
- type Error = TryFromIntError;
-
- /// Try to create the target number type from a source
- /// number type. This returns an error if the source value
- /// is outside of the range of the target type.
- #[inline]
- fn try_from(u: $source) -> Result<$target, TryFromIntError> {
- if u >= 0 {
- Ok(u as $target)
- } else {
- Err(TryFromIntError(()))
- }
- }
- }
- )*}
-}
-
-// unsigned to signed (only positive bound)
-macro_rules! try_from_upper_bounded {
- ($source:ty, $($target:ty),*) => {$(
- #[stable(feature = "try_from", since = "1.34.0")]
- impl TryFrom<$source> for $target {
- type Error = TryFromIntError;
-
- /// Try to create the target number type from a source
- /// number type. This returns an error if the source value
- /// is outside of the range of the target type.
- #[inline]
- fn try_from(u: $source) -> Result<$target, TryFromIntError> {
- if u > (<$target>::max_value() as $source) {
- Err(TryFromIntError(()))
- } else {
- Ok(u as $target)
- }
- }
- }
- )*}
-}
-
-// all other cases
-macro_rules! try_from_both_bounded {
- ($source:ty, $($target:ty),*) => {$(
- #[stable(feature = "try_from", since = "1.34.0")]
- impl TryFrom<$source> for $target {
- type Error = TryFromIntError;
-
- /// Try to create the target number type from a source
- /// number type. This returns an error if the source value
- /// is outside of the range of the target type.
- #[inline]
- fn try_from(u: $source) -> Result<$target, TryFromIntError> {
- let min = <$target>::min_value() as $source;
- let max = <$target>::max_value() as $source;
- if u < min || u > max {
- Err(TryFromIntError(()))
- } else {
- Ok(u as $target)
- }
- }
- }
- )*}
-}
-
-macro_rules! rev {
- ($mac:ident, $source:ty, $($target:ty),*) => {$(
- $mac!($target, $source);
- )*}
-}
-
-// intra-sign conversions
-try_from_upper_bounded!(u16, u8);
-try_from_upper_bounded!(u32, u16, u8);
-try_from_upper_bounded!(u64, u32, u16, u8);
-try_from_upper_bounded!(u128, u64, u32, u16, u8);
-
-try_from_both_bounded!(i16, i8);
-try_from_both_bounded!(i32, i16, i8);
-try_from_both_bounded!(i64, i32, i16, i8);
-try_from_both_bounded!(i128, i64, i32, i16, i8);
-
-// unsigned-to-signed
-try_from_upper_bounded!(u8, i8);
-try_from_upper_bounded!(u16, i8, i16);
-try_from_upper_bounded!(u32, i8, i16, i32);
-try_from_upper_bounded!(u64, i8, i16, i32, i64);
-try_from_upper_bounded!(u128, i8, i16, i32, i64, i128);
-
-// signed-to-unsigned
-try_from_lower_bounded!(i8, u8, u16, u32, u64, u128);
-try_from_lower_bounded!(i16, u16, u32, u64, u128);
-try_from_lower_bounded!(i32, u32, u64, u128);
-try_from_lower_bounded!(i64, u64, u128);
-try_from_lower_bounded!(i128, u128);
-try_from_both_bounded!(i16, u8);
-try_from_both_bounded!(i32, u16, u8);
-try_from_both_bounded!(i64, u32, u16, u8);
-try_from_both_bounded!(i128, u64, u32, u16, u8);
-
-// usize/isize
-try_from_upper_bounded!(usize, isize);
-try_from_lower_bounded!(isize, usize);
-
-#[cfg(target_pointer_width = "16")]
-mod ptr_try_from_impls {
- use super::TryFromIntError;
- use crate::convert::TryFrom;
-
- try_from_upper_bounded!(usize, u8);
- try_from_unbounded!(usize, u16, u32, u64, u128);
- try_from_upper_bounded!(usize, i8, i16);
- try_from_unbounded!(usize, i32, i64, i128);
-
- try_from_both_bounded!(isize, u8);
- try_from_lower_bounded!(isize, u16, u32, u64, u128);
- try_from_both_bounded!(isize, i8);
- try_from_unbounded!(isize, i16, i32, i64, i128);
-
- rev!(try_from_upper_bounded, usize, u32, u64, u128);
- rev!(try_from_lower_bounded, usize, i8, i16);
- rev!(try_from_both_bounded, usize, i32, i64, i128);
-
- rev!(try_from_upper_bounded, isize, u16, u32, u64, u128);
- rev!(try_from_both_bounded, isize, i32, i64, i128);
-}
-
-#[cfg(target_pointer_width = "32")]
-mod ptr_try_from_impls {
- use super::TryFromIntError;
- use crate::convert::TryFrom;
-
- try_from_upper_bounded!(usize, u8, u16);
- try_from_unbounded!(usize, u32, u64, u128);
- try_from_upper_bounded!(usize, i8, i16, i32);
- try_from_unbounded!(usize, i64, i128);
-
- try_from_both_bounded!(isize, u8, u16);
- try_from_lower_bounded!(isize, u32, u64, u128);
- try_from_both_bounded!(isize, i8, i16);
- try_from_unbounded!(isize, i32, i64, i128);
-
- rev!(try_from_unbounded, usize, u32);
- rev!(try_from_upper_bounded, usize, u64, u128);
- rev!(try_from_lower_bounded, usize, i8, i16, i32);
- rev!(try_from_both_bounded, usize, i64, i128);
-
- rev!(try_from_unbounded, isize, u16);
- rev!(try_from_upper_bounded, isize, u32, u64, u128);
- rev!(try_from_unbounded, isize, i32);
- rev!(try_from_both_bounded, isize, i64, i128);
-}
-
-#[cfg(target_pointer_width = "64")]
-mod ptr_try_from_impls {
- use super::TryFromIntError;
- use crate::convert::TryFrom;
-
- try_from_upper_bounded!(usize, u8, u16, u32);
- try_from_unbounded!(usize, u64, u128);
- try_from_upper_bounded!(usize, i8, i16, i32, i64);
- try_from_unbounded!(usize, i128);
-
- try_from_both_bounded!(isize, u8, u16, u32);
- try_from_lower_bounded!(isize, u64, u128);
- try_from_both_bounded!(isize, i8, i16, i32);
- try_from_unbounded!(isize, i64, i128);
-
- rev!(try_from_unbounded, usize, u32, u64);
- rev!(try_from_upper_bounded, usize, u128);
- rev!(try_from_lower_bounded, usize, i8, i16, i32, i64);
- rev!(try_from_both_bounded, usize, i128);
-
- rev!(try_from_unbounded, isize, u16, u32);
- rev!(try_from_upper_bounded, isize, u64, u128);
- rev!(try_from_unbounded, isize, i32, i64);
- rev!(try_from_both_bounded, isize, i128);
-}
-
#[doc(hidden)]
trait FromStrRadixHelper: PartialOrd + Copy {
fn min_value() -> Self;
#[stable(feature = "rust1", since = "1.0.0")]
pub use crate::num::dec2flt::ParseFloatError;
-
-// Conversion traits for primitive integer and float types
-// Conversions T -> T are covered by a blanket impl and therefore excluded
-// Some conversions from and to usize/isize are not implemented due to portability concerns
-macro_rules! impl_from {
- ($Small: ty, $Large: ty, #[$attr:meta], $doc: expr) => {
- #[$attr]
- #[doc = $doc]
- impl From<$Small> for $Large {
- #[inline]
- fn from(small: $Small) -> $Large {
- small as $Large
- }
- }
- };
- ($Small: ty, $Large: ty, #[$attr:meta]) => {
- impl_from!($Small,
- $Large,
- #[$attr],
- concat!("Converts `",
- stringify!($Small),
- "` to `",
- stringify!($Large),
- "` losslessly."));
- }
-}
-
-macro_rules! impl_from_bool {
- ($target: ty, #[$attr:meta]) => {
- impl_from!(bool, $target, #[$attr], concat!("Converts a `bool` to a `",
- stringify!($target), "`. The resulting value is `0` for `false` and `1` for `true`
-values.
-
-# Examples
-
-```
-assert_eq!(", stringify!($target), "::from(true), 1);
-assert_eq!(", stringify!($target), "::from(false), 0);
-```"));
- };
-}
-
-// Bool -> Any
-impl_from_bool! { u8, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { u16, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { u32, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { u64, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { u128, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { usize, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i8, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i16, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i32, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i64, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { i128, #[stable(feature = "from_bool", since = "1.28.0")] }
-impl_from_bool! { isize, #[stable(feature = "from_bool", since = "1.28.0")] }
-
-// Unsigned -> Unsigned
-impl_from! { u8, u16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, u128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u8, usize, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, u128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u32, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u32, u128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u64, u128, #[stable(feature = "i128", since = "1.26.0")] }
-
-// Signed -> Signed
-impl_from! { i8, i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i8, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i8, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i8, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { i8, isize, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i16, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i16, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i16, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { i32, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { i32, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { i64, i128, #[stable(feature = "i128", since = "1.26.0")] }
-
-// Unsigned -> Signed
-impl_from! { u8, i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u8, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u16, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u16, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u32, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
-impl_from! { u32, i128, #[stable(feature = "i128", since = "1.26.0")] }
-impl_from! { u64, i128, #[stable(feature = "i128", since = "1.26.0")] }
-
-// The C99 standard defines bounds on INTPTR_MIN, INTPTR_MAX, and UINTPTR_MAX
-// which imply that pointer-sized integers must be at least 16 bits:
-// https://port70.net/~nsz/c/c99/n1256.html#7.18.2.4
-impl_from! { u16, usize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
-impl_from! { u8, isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
-impl_from! { i16, isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
-
-// RISC-V defines the possibility of a 128-bit address space (RV128).
-
-// CHERI proposes 256-bit “capabilities”. Unclear if this would be relevant to usize/isize.
-// https://www.cl.cam.ac.uk/research/security/ctsrd/pdfs/20171017a-cheri-poster.pdf
-// http://www.csl.sri.com/users/neumann/2012resolve-cheri.pdf
-
-
-// Note: integers can only be represented with full precision in a float if
-// they fit in the significand, which is 24 bits in f32 and 53 bits in f64.
-// Lossy float conversions are not implemented at this time.
-
-// Signed -> Float
-impl_from! { i8, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { i8, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { i16, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { i16, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { i32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-
-// Unsigned -> Float
-impl_from! { u8, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { u8, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { u16, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { u16, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-impl_from! { u32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
-
-// Float -> Float
-impl_from! { f32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
projects / rust.git / commitdiff