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SimonSapinSimonSapin
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Move numeric From and TryFrom impls to libcore/convert/num.rs
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.
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‎src/libcore/convert/num.rs

+331
Original file line numberDiff line numberDiff line change
@@ -1,3 +1,6 @@
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use super::{From, TryFrom};
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use crate::num::TryFromIntError;
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mod private {
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/// This trait being unreachable from outside the crate
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/// prevents other implementations of the `FloatToInt` trait,
@@ -36,3 +39,331 @@ macro_rules! impl_float_to_int {
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impl_float_to_int!(f32 => u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize);
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impl_float_to_int!(f64 => u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize);
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// Conversion traits for primitive integer and float types
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// Conversions T -> T are covered by a blanket impl and therefore excluded
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// Some conversions from and to usize/isize are not implemented due to portability concerns
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macro_rules! impl_from {
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($Small: ty, $Large: ty, #[$attr:meta], $doc: expr) => {
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#[$attr]
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#[doc = $doc]
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impl From<$Small> for $Large {
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#[inline]
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fn from(small: $Small) -> $Large {
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small as $Large
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}
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}
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};
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($Small: ty, $Large: ty, #[$attr:meta]) => {
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impl_from!($Small,
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$Large,
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#[$attr],
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concat!("Converts `",
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stringify!($Small),
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"` to `",
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stringify!($Large),
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"` losslessly."));
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}
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}
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macro_rules! impl_from_bool {
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($target: ty, #[$attr:meta]) => {
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impl_from!(bool, $target, #[$attr], concat!("Converts a `bool` to a `",
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stringify!($target), "`. The resulting value is `0` for `false` and `1` for `true`
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values.
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# Examples
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```
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assert_eq!(", stringify!($target), "::from(true), 1);
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assert_eq!(", stringify!($target), "::from(false), 0);
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```"));
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};
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}
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// Bool -> Any
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impl_from_bool! { u8, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { u16, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { u32, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { u64, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { u128, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { usize, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { i8, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { i16, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { i32, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { i64, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { i128, #[stable(feature = "from_bool", since = "1.28.0")] }
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impl_from_bool! { isize, #[stable(feature = "from_bool", since = "1.28.0")] }
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// Unsigned -> Unsigned
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impl_from! { u8, u16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u8, u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u8, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u8, u128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { u8, usize, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u16, u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u16, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u16, u128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { u32, u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u32, u128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { u64, u128, #[stable(feature = "i128", since = "1.26.0")] }
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// Signed -> Signed
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impl_from! { i8, i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { i8, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { i8, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { i8, i128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { i8, isize, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { i16, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { i16, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { i16, i128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { i32, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { i32, i128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { i64, i128, #[stable(feature = "i128", since = "1.26.0")] }
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// Unsigned -> Signed
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impl_from! { u8, i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u8, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u8, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u8, i128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { u16, i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u16, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u16, i128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { u32, i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")] }
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impl_from! { u32, i128, #[stable(feature = "i128", since = "1.26.0")] }
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impl_from! { u64, i128, #[stable(feature = "i128", since = "1.26.0")] }
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// The C99 standard defines bounds on INTPTR_MIN, INTPTR_MAX, and UINTPTR_MAX
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// which imply that pointer-sized integers must be at least 16 bits:
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// https://port70.net/~nsz/c/c99/n1256.html#7.18.2.4
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impl_from! { u16, usize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
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impl_from! { u8, isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
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impl_from! { i16, isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")] }
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// RISC-V defines the possibility of a 128-bit address space (RV128).
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// CHERI proposes 256-bit “capabilities”. Unclear if this would be relevant to usize/isize.
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// https://www.cl.cam.ac.uk/research/security/ctsrd/pdfs/20171017a-cheri-poster.pdf
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// http://www.csl.sri.com/users/neumann/2012resolve-cheri.pdf
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// Note: integers can only be represented with full precision in a float if
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// they fit in the significand, which is 24 bits in f32 and 53 bits in f64.
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// Lossy float conversions are not implemented at this time.
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// Signed -> Float
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impl_from! { i8, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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impl_from! { i8, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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impl_from! { i16, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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impl_from! { i16, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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impl_from! { i32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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// Unsigned -> Float
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impl_from! { u8, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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impl_from! { u8, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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impl_from! { u16, f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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impl_from! { u16, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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impl_from! { u32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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// Float -> Float
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impl_from! { f32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
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// no possible bounds violation
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macro_rules! try_from_unbounded {
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($source:ty, $($target:ty),*) => {$(
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#[stable(feature = "try_from", since = "1.34.0")]
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impl TryFrom<$source> for $target {
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type Error = TryFromIntError;
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/// Try to create the target number type from a source
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/// number type. This returns an error if the source value
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/// is outside of the range of the target type.
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#[inline]
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fn try_from(value: $source) -> Result<Self, Self::Error> {
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Ok(value as $target)
184+
}
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}
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)*}
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}
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// only negative bounds
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macro_rules! try_from_lower_bounded {
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($source:ty, $($target:ty),*) => {$(
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#[stable(feature = "try_from", since = "1.34.0")]
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impl TryFrom<$source> for $target {
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type Error = TryFromIntError;
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/// Try to create the target number type from a source
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/// number type. This returns an error if the source value
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/// is outside of the range of the target type.
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#[inline]
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fn try_from(u: $source) -> Result<$target, TryFromIntError> {
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if u >= 0 {
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Ok(u as $target)
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} else {
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Err(TryFromIntError(()))
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}
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}
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}
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)*}
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}
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// unsigned to signed (only positive bound)
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macro_rules! try_from_upper_bounded {
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($source:ty, $($target:ty),*) => {$(
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#[stable(feature = "try_from", since = "1.34.0")]
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impl TryFrom<$source> for $target {
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type Error = TryFromIntError;
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/// Try to create the target number type from a source
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/// number type. This returns an error if the source value
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/// is outside of the range of the target type.
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#[inline]
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fn try_from(u: $source) -> Result<$target, TryFromIntError> {
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if u > (<$target>::max_value() as $source) {
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Err(TryFromIntError(()))
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} else {
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Ok(u as $target)
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}
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}
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}
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)*}
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}
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// all other cases
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macro_rules! try_from_both_bounded {
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($source:ty, $($target:ty),*) => {$(
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#[stable(feature = "try_from", since = "1.34.0")]
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impl TryFrom<$source> for $target {
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type Error = TryFromIntError;
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/// Try to create the target number type from a source
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/// number type. This returns an error if the source value
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/// is outside of the range of the target type.
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#[inline]
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fn try_from(u: $source) -> Result<$target, TryFromIntError> {
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let min = <$target>::min_value() as $source;
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let max = <$target>::max_value() as $source;
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if u < min || u > max {
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Err(TryFromIntError(()))
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} else {
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Ok(u as $target)
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}
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}
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}
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)*}
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}
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macro_rules! rev {
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($mac:ident, $source:ty, $($target:ty),*) => {$(
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$mac!($target, $source);
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)*}
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}
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// intra-sign conversions
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try_from_upper_bounded!(u16, u8);
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try_from_upper_bounded!(u32, u16, u8);
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try_from_upper_bounded!(u64, u32, u16, u8);
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try_from_upper_bounded!(u128, u64, u32, u16, u8);
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try_from_both_bounded!(i16, i8);
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try_from_both_bounded!(i32, i16, i8);
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try_from_both_bounded!(i64, i32, i16, i8);
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try_from_both_bounded!(i128, i64, i32, i16, i8);
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// unsigned-to-signed
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try_from_upper_bounded!(u8, i8);
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try_from_upper_bounded!(u16, i8, i16);
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try_from_upper_bounded!(u32, i8, i16, i32);
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try_from_upper_bounded!(u64, i8, i16, i32, i64);
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try_from_upper_bounded!(u128, i8, i16, i32, i64, i128);
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// signed-to-unsigned
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try_from_lower_bounded!(i8, u8, u16, u32, u64, u128);
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try_from_lower_bounded!(i16, u16, u32, u64, u128);
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try_from_lower_bounded!(i32, u32, u64, u128);
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try_from_lower_bounded!(i64, u64, u128);
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try_from_lower_bounded!(i128, u128);
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try_from_both_bounded!(i16, u8);
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try_from_both_bounded!(i32, u16, u8);
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try_from_both_bounded!(i64, u32, u16, u8);
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try_from_both_bounded!(i128, u64, u32, u16, u8);
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// usize/isize
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try_from_upper_bounded!(usize, isize);
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try_from_lower_bounded!(isize, usize);
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#[cfg(target_pointer_width = "16")]
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mod ptr_try_from_impls {
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use super::TryFromIntError;
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use crate::convert::TryFrom;
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try_from_upper_bounded!(usize, u8);
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try_from_unbounded!(usize, u16, u32, u64, u128);
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try_from_upper_bounded!(usize, i8, i16);
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try_from_unbounded!(usize, i32, i64, i128);
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try_from_both_bounded!(isize, u8);
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try_from_lower_bounded!(isize, u16, u32, u64, u128);
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try_from_both_bounded!(isize, i8);
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try_from_unbounded!(isize, i16, i32, i64, i128);
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rev!(try_from_upper_bounded, usize, u32, u64, u128);
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rev!(try_from_lower_bounded, usize, i8, i16);
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rev!(try_from_both_bounded, usize, i32, i64, i128);
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rev!(try_from_upper_bounded, isize, u16, u32, u64, u128);
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rev!(try_from_both_bounded, isize, i32, i64, i128);
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}
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#[cfg(target_pointer_width = "32")]
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mod ptr_try_from_impls {
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use super::TryFromIntError;
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use crate::convert::TryFrom;
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try_from_upper_bounded!(usize, u8, u16);
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try_from_unbounded!(usize, u32, u64, u128);
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try_from_upper_bounded!(usize, i8, i16, i32);
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try_from_unbounded!(usize, i64, i128);
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try_from_both_bounded!(isize, u8, u16);
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try_from_lower_bounded!(isize, u32, u64, u128);
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try_from_both_bounded!(isize, i8, i16);
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try_from_unbounded!(isize, i32, i64, i128);
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rev!(try_from_unbounded, usize, u32);
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rev!(try_from_upper_bounded, usize, u64, u128);
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rev!(try_from_lower_bounded, usize, i8, i16, i32);
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rev!(try_from_both_bounded, usize, i64, i128);
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rev!(try_from_unbounded, isize, u16);
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rev!(try_from_upper_bounded, isize, u32, u64, u128);
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rev!(try_from_unbounded, isize, i32);
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rev!(try_from_both_bounded, isize, i64, i128);
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}
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#[cfg(target_pointer_width = "64")]
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mod ptr_try_from_impls {
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use super::TryFromIntError;
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use crate::convert::TryFrom;
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try_from_upper_bounded!(usize, u8, u16, u32);
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try_from_unbounded!(usize, u64, u128);
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try_from_upper_bounded!(usize, i8, i16, i32, i64);
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try_from_unbounded!(usize, i128);
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try_from_both_bounded!(isize, u8, u16, u32);
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try_from_lower_bounded!(isize, u64, u128);
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try_from_both_bounded!(isize, i8, i16, i32);
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try_from_unbounded!(isize, i64, i128);
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rev!(try_from_unbounded, usize, u32, u64);
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rev!(try_from_upper_bounded, usize, u128);
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rev!(try_from_lower_bounded, usize, i8, i16, i32, i64);
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rev!(try_from_both_bounded, usize, i128);
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rev!(try_from_unbounded, isize, u16, u32);
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rev!(try_from_upper_bounded, isize, u64, u128);
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rev!(try_from_unbounded, isize, i32, i64);
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rev!(try_from_both_bounded, isize, i128);
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}

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