From 50868c60d2d37cd68ed545f180faf66b96e2271b Mon Sep 17 00:00:00 2001 From: Josh Stone Date: Sun, 11 Mar 2018 01:37:00 -0800 Subject: [PATCH] Refactor to_primitive_int/uint macros --- src/cast.rs | 157 ++++++++++++++++++++++------------------------------ 1 file changed, 67 insertions(+), 90 deletions(-) diff --git a/src/cast.rs b/src/cast.rs index 3a83b06..694b0e5 100644 --- a/src/cast.rs +++ b/src/cast.rs @@ -4,8 +4,6 @@ use core::{f32, f64}; use core::mem::size_of; use core::num::Wrapping; -use identities::Zero; -use bounds::Bounded; use float::FloatCore; /// A generic trait for converting a value to a number. @@ -79,62 +77,52 @@ pub trait ToPrimitive { } macro_rules! impl_to_primitive_int_to_int { - ($SrcT:ty, $DstT:ty, $slf:expr) => ( - { - if size_of::<$SrcT>() <= size_of::<$DstT>() { - Some($slf as $DstT) - } else { - let n = $slf as i64; - let min_value: $DstT = Bounded::min_value(); - let max_value: $DstT = Bounded::max_value(); - if min_value as i64 <= n && n <= max_value as i64 { - Some($slf as $DstT) - } else { - None - } - } - } - ) -} - -macro_rules! impl_to_primitive_int_to_uint { - ($SrcT:ty, $DstT:ty, $slf:expr) => ( - { - let zero: $SrcT = Zero::zero(); - let max_value: $DstT = Bounded::max_value(); - if zero <= $slf && $slf as u64 <= max_value as u64 { - Some($slf as $DstT) + ($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( + #[inline] + fn $method(&self) -> Option<$DstT> { + let min = $DstT::MIN as $SrcT; + let max = $DstT::MAX as $SrcT; + if size_of::<$SrcT>() <= size_of::<$DstT>() || (min <= *self && *self <= max) { + Some(*self as $DstT) } else { None } } - ) + )*} +} + +macro_rules! impl_to_primitive_int_to_uint { + ($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( + #[inline] + fn $method(&self) -> Option<$DstT> { + let max = $DstT::MAX as u64; + if 0 <= *self && (size_of::<$SrcT>() < size_of::<$DstT>() || *self as u64 <= max) { + Some(*self as $DstT) + } else { + None + } + } + )*} } macro_rules! impl_to_primitive_int { - ($T:ty) => ( + ($T:ident) => ( impl ToPrimitive for $T { - #[inline] - fn to_isize(&self) -> Option { impl_to_primitive_int_to_int!($T, isize, *self) } - #[inline] - fn to_i8(&self) -> Option { impl_to_primitive_int_to_int!($T, i8, *self) } - #[inline] - fn to_i16(&self) -> Option { impl_to_primitive_int_to_int!($T, i16, *self) } - #[inline] - fn to_i32(&self) -> Option { impl_to_primitive_int_to_int!($T, i32, *self) } - #[inline] - fn to_i64(&self) -> Option { impl_to_primitive_int_to_int!($T, i64, *self) } + impl_to_primitive_int_to_int! { $T: + fn to_isize -> isize; + fn to_i8 -> i8; + fn to_i16 -> i16; + fn to_i32 -> i32; + fn to_i64 -> i64; + } - #[inline] - fn to_usize(&self) -> Option { impl_to_primitive_int_to_uint!($T, usize, *self) } - #[inline] - fn to_u8(&self) -> Option { impl_to_primitive_int_to_uint!($T, u8, *self) } - #[inline] - fn to_u16(&self) -> Option { impl_to_primitive_int_to_uint!($T, u16, *self) } - #[inline] - fn to_u32(&self) -> Option { impl_to_primitive_int_to_uint!($T, u32, *self) } - #[inline] - fn to_u64(&self) -> Option { impl_to_primitive_int_to_uint!($T, u64, *self) } + impl_to_primitive_int_to_uint! { $T: + fn to_usize -> usize; + fn to_u8 -> u8; + fn to_u16 -> u16; + fn to_u32 -> u32; + fn to_u64 -> u64; + } #[inline] fn to_f32(&self) -> Option { Some(*self as f32) } @@ -151,62 +139,51 @@ impl_to_primitive_int!(i32); impl_to_primitive_int!(i64); macro_rules! impl_to_primitive_uint_to_int { - ($DstT:ty, $slf:expr) => ( - { - let max_value: $DstT = Bounded::max_value(); - if $slf as u64 <= max_value as u64 { - Some($slf as $DstT) + ($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( + #[inline] + fn $method(&self) -> Option<$DstT> { + let max = $DstT::MAX as u64; + if size_of::<$SrcT>() < size_of::<$DstT>() || *self as u64 <= max { + Some(*self as $DstT) } else { None } } - ) + )*} } macro_rules! impl_to_primitive_uint_to_uint { - ($SrcT:ty, $DstT:ty, $slf:expr) => ( - { - if size_of::<$SrcT>() <= size_of::<$DstT>() { - Some($slf as $DstT) + ($SrcT:ident : $( fn $method:ident -> $DstT:ident ; )*) => {$( + #[inline] + fn $method(&self) -> Option<$DstT> { + let max = $DstT::MAX as $SrcT; + if size_of::<$SrcT>() <= size_of::<$DstT>() || *self <= max { + Some(*self as $DstT) } else { - let zero: $SrcT = Zero::zero(); - let max_value: $DstT = Bounded::max_value(); - if zero <= $slf && $slf as u64 <= max_value as u64 { - Some($slf as $DstT) - } else { - None - } + None } } - ) + )*} } macro_rules! impl_to_primitive_uint { - ($T:ty) => ( + ($T:ident) => ( impl ToPrimitive for $T { - #[inline] - fn to_isize(&self) -> Option { impl_to_primitive_uint_to_int!(isize, *self) } - #[inline] - fn to_i8(&self) -> Option { impl_to_primitive_uint_to_int!(i8, *self) } - #[inline] - fn to_i16(&self) -> Option { impl_to_primitive_uint_to_int!(i16, *self) } - #[inline] - fn to_i32(&self) -> Option { impl_to_primitive_uint_to_int!(i32, *self) } - #[inline] - fn to_i64(&self) -> Option { impl_to_primitive_uint_to_int!(i64, *self) } - - #[inline] - fn to_usize(&self) -> Option { - impl_to_primitive_uint_to_uint!($T, usize, *self) + impl_to_primitive_uint_to_int! { $T: + fn to_isize -> isize; + fn to_i8 -> i8; + fn to_i16 -> i16; + fn to_i32 -> i32; + fn to_i64 -> i64; + } + + impl_to_primitive_uint_to_uint! { $T: + fn to_usize -> usize; + fn to_u8 -> u8; + fn to_u16 -> u16; + fn to_u32 -> u32; + fn to_u64 -> u64; } - #[inline] - fn to_u8(&self) -> Option { impl_to_primitive_uint_to_uint!($T, u8, *self) } - #[inline] - fn to_u16(&self) -> Option { impl_to_primitive_uint_to_uint!($T, u16, *self) } - #[inline] - fn to_u32(&self) -> Option { impl_to_primitive_uint_to_uint!($T, u32, *self) } - #[inline] - fn to_u64(&self) -> Option { impl_to_primitive_uint_to_uint!($T, u64, *self) } #[inline] fn to_f32(&self) -> Option { Some(*self as f32) }