From a213ff82998ef91fa793883c2f2ebbc574967500 Mon Sep 17 00:00:00 2001 From: Simon Sapin Date: Mon, 2 Dec 2019 09:44:48 +0100 Subject: [PATCH] Move numeric `From` and `TryFrom` impls to `libcore/convert/num.rs` MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This makes `libcore/num/mod.rs` slightly smaller. It’s still 4911 lines and not easy to navigate. This doesn’t change any public API. --- src/libcore/convert/num.rs | 331 +++++++++++++++++++++++++++++++++++++ src/libcore/num/mod.rs | 331 +------------------------------------ 2 files changed, 332 insertions(+), 330 deletions(-) diff --git a/src/libcore/convert/num.rs b/src/libcore/convert/num.rs index 076a1107479e7..0877dacb38dd2 100644 --- a/src/libcore/convert/num.rs +++ b/src/libcore/convert/num.rs @@ -1,3 +1,6 @@ +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, @@ -36,3 +39,331 @@ macro_rules! impl_float_to_int { 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 { + 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); +} diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs index 4313248f2636a..585f144cf8a9f 100644 --- a/src/libcore/num/mod.rs +++ b/src/libcore/num/mod.rs @@ -4,7 +4,6 @@ #![stable(feature = "rust1", since = "1.0.0")] -use crate::convert::TryFrom; use crate::fmt; use crate::intrinsics; use crate::mem; @@ -4701,7 +4700,7 @@ from_str_radix_int_impl! { isize i8 i16 i32 i64 i128 usize u8 u16 u32 u64 u128 } /// 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", @@ -4728,206 +4727,6 @@ impl From for TryFromIntError { } } -// 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 { - 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; @@ -5110,131 +4909,3 @@ impl fmt::Display for ParseIntError { #[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")] }