Refactor to_primitive_int/uint macros

This commit is contained in:
Josh Stone 2018-03-11 01:37:00 -08:00
parent 6d7bbb1b53
commit 50868c60d2
1 changed files with 67 additions and 90 deletions

View File

@ -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 $T {
#[inline]
fn to_isize(&self) -> Option<isize> { impl_to_primitive_int_to_int!($T, isize, *self) }
#[inline]
fn to_i8(&self) -> Option<i8> { impl_to_primitive_int_to_int!($T, i8, *self) }
#[inline]
fn to_i16(&self) -> Option<i16> { impl_to_primitive_int_to_int!($T, i16, *self) }
#[inline]
fn to_i32(&self) -> Option<i32> { impl_to_primitive_int_to_int!($T, i32, *self) }
#[inline]
fn to_i64(&self) -> Option<i64> { impl_to_primitive_int_to_int!($T, i64, *self) }
impl_to_primitive_int_to_int! { $T:
fn to_isize -> isize;
fn to_i8 -> i8;
fn to_i16 -> i16;
fn to_i32 -> i32;
fn to_i64 -> i64;
}
#[inline]
fn to_usize(&self) -> Option<usize> { impl_to_primitive_int_to_uint!($T, usize, *self) }
#[inline]
fn to_u8(&self) -> Option<u8> { impl_to_primitive_int_to_uint!($T, u8, *self) }
#[inline]
fn to_u16(&self) -> Option<u16> { impl_to_primitive_int_to_uint!($T, u16, *self) }
#[inline]
fn to_u32(&self) -> Option<u32> { impl_to_primitive_int_to_uint!($T, u32, *self) }
#[inline]
fn to_u64(&self) -> Option<u64> { impl_to_primitive_int_to_uint!($T, u64, *self) }
impl_to_primitive_int_to_uint! { $T:
fn to_usize -> usize;
fn to_u8 -> u8;
fn to_u16 -> u16;
fn to_u32 -> u32;
fn to_u64 -> u64;
}
#[inline]
fn to_f32(&self) -> Option<f32> { Some(*self as f32) }
@ -151,62 +139,51 @@ impl_to_primitive_int!(i32);
impl_to_primitive_int!(i64);
macro_rules! impl_to_primitive_uint_to_int {
($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 $T {
#[inline]
fn to_isize(&self) -> Option<isize> { impl_to_primitive_uint_to_int!(isize, *self) }
#[inline]
fn to_i8(&self) -> Option<i8> { impl_to_primitive_uint_to_int!(i8, *self) }
#[inline]
fn to_i16(&self) -> Option<i16> { impl_to_primitive_uint_to_int!(i16, *self) }
#[inline]
fn to_i32(&self) -> Option<i32> { impl_to_primitive_uint_to_int!(i32, *self) }
#[inline]
fn to_i64(&self) -> Option<i64> { impl_to_primitive_uint_to_int!(i64, *self) }
#[inline]
fn to_usize(&self) -> Option<usize> {
impl_to_primitive_uint_to_uint!($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! { $T:
fn to_usize -> usize;
fn to_u8 -> u8;
fn to_u16 -> u16;
fn to_u32 -> u32;
fn to_u64 -> u64;
}
#[inline]
fn to_u8(&self) -> Option<u8> { impl_to_primitive_uint_to_uint!($T, u8, *self) }
#[inline]
fn to_u16(&self) -> Option<u16> { impl_to_primitive_uint_to_uint!($T, u16, *self) }
#[inline]
fn to_u32(&self) -> Option<u32> { impl_to_primitive_uint_to_uint!($T, u32, *self) }
#[inline]
fn to_u64(&self) -> Option<u64> { impl_to_primitive_uint_to_uint!($T, u64, *self) }
#[inline]
fn to_f32(&self) -> Option<f32> { Some(*self as f32) }