diff options
Diffstat (limited to 'src/lib.rs')
| -rw-r--r-- | src/lib.rs | 73 |
1 files changed, 33 insertions, 40 deletions
@@ -4,8 +4,6 @@ //! Use these functions to perform a cast from any other numeric primitive: //! //! ``` -//! extern crate cast; -//! //! use cast::{u8, u16, Error}; //! //! # fn main() { @@ -28,8 +26,6 @@ //! be in the same scope: //! //! ``` -//! extern crate cast; -//! //! use std::u8; //! use cast::{u8, u16}; //! @@ -47,8 +43,6 @@ //! `cast` static method: //! //! ``` -//! extern crate cast; -//! //! use std::os::raw::c_ulonglong; //! // NOTE avoid shadowing `std::convert::From` - cf. rust-lang/rfcs#1311 //! use cast::From as _0; @@ -63,8 +57,6 @@ //! casted to `u32`. //! //! ``` -//! extern crate cast; -//! //! fn to_u32<T>(x: T) -> u32 //! // reads as: "where u32 can be casted from T with output u32" //! where u32: cast::From<T, Output=u32>, @@ -83,8 +75,9 @@ //! //! ## Minimal Supported Rust Version //! -//! This crate is guaranteed to compile on stable Rust 1.13 and up. It *might* compile on older -//! versions but that may change in any new patch release. +//! This crate is guaranteed to compile *as a dependency* on stable Rust 1.31 and up. +//! It's not guaranteed that `cargo test`-ing this crate follows the MSRV. +//! It *might* compile on older versions but that may change in any new patch release. //! //! ## Building without `std` //! @@ -95,14 +88,11 @@ //! cast = { version = "*", default-features = false } //! ``` -#![deny(missing_docs)] -#![deny(warnings)] #![allow(const_err)] #![cfg_attr(not(feature = "std"), no_std)] -#![cfg_attr(all(feature = "x128", not(stable_i128)), feature(i128_type, i128))] - -#[cfg(feature = "std")] -extern crate core; +#![deny(missing_docs)] +#![deny(unsafe_code)] +#![deny(warnings)] #[cfg(test)] #[macro_use] @@ -144,7 +134,7 @@ impl Error { } impl fmt::Display for Error { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!(f, "{}", self.description_helper()) } } @@ -162,7 +152,7 @@ pub trait From<Src> { type Output; /// Checked cast from `Src` to `Self` - fn cast(Src) -> Self::Output; + fn cast(_: Src) -> Self::Output; } macro_rules! fns { @@ -181,7 +171,6 @@ macro_rules! fns { fns!(f32, f64, i8, i16, i32, i64, isize, u8, u16, u32, u64, usize); -#[cfg(feature = "x128")] fns!(i128, u128); /// `$dst` can hold any value of `$src` @@ -276,7 +265,7 @@ macro_rules! from_signed { /// From a float `$src` to an integer `$dst` macro_rules! from_float { - ($($src:ident, $usrc:ident => $($dst:ident),+);+;) => { + ($($src:ident => $($dst:ident),+);+;) => { $( $( impl From<$src> for $dst { @@ -292,13 +281,19 @@ macro_rules! from_float { src == $src::NEG_INFINITY { Error::Infinite } else if { - // we subtract 1 ULP (unit of least precision) here because some - // lossy conversions like `u64::MAX as f64` round *up* and we want - // to avoid this evaluating to false in that case - use core::mem::transmute; - let max = unsafe { - transmute::<_, $src>(transmute::<_, $usrc>($dst::MAX as $src) - 1) + // this '$dst::BITS' works on 1.31.0 (MSRV) + let dst_bits = core::mem::size_of::<$dst>() as u32 * 8; + let lossless = dst_bits < core::$src::MANTISSA_DIGITS; + + let max = if lossless { + $dst::MAX as $src + } else { + // we subtract 1 ULP (unit of least precision) here because some + // lossy conversions like `u64::MAX as f64` round *up* and we want + // to avoid the check below evaluating to false in that case + $src::from_bits(($dst::MAX as $src).to_bits() - 1) }; + src > max } { Error::Overflow @@ -325,7 +320,6 @@ macro_rules! from_float { /// From a float `$src` to an integer `$dst`, where $dst is large enough to contain /// all values of `$src`. We can't ever overflow here -#[cfg(feature = "x128")] macro_rules! from_float_dst { ($($src:ident => $($dst:ident),+);+;) => { $( @@ -359,7 +353,7 @@ macro_rules! from_float_dst { #[cfg(target_pointer_width = "32")] mod _32 { - use {Error, From}; + use crate::{Error, From}; // Signed promotion! { @@ -410,14 +404,14 @@ mod _32 { } from_float! { - f32, u32 => i8, i16, i32, isize, i64, u8, u16, u32, usize, u64; - f64, u64 => i8, i16, i32, isize, i64, u8, u16, u32, usize, u64; + f32 => i8, i16, i32, isize, i64, u8, u16, u32, usize, u64; + f64 => i8, i16, i32, isize, i64, u8, u16, u32, usize, u64; } } #[cfg(target_pointer_width = "64")] mod _64 { - use {Error, From}; + use crate::{Error, From}; // Signed promotion! { @@ -468,14 +462,13 @@ mod _64 { } from_float! { - f32, u32 => i8, i16, i32, i64, isize, u8, u16, u32, u64, usize; - f64, u64 => i8, i16, i32, i64, isize, u8, u16, u32, u64, usize; + f32 => i8, i16, i32, i64, isize, u8, u16, u32, u64, usize; + f64 => i8, i16, i32, i64, isize, u8, u16, u32, u64, usize; } } -#[cfg(feature = "x128")] mod _x128 { - use {Error, From}; + use crate::{Error, From}; // Signed promotion! { @@ -515,13 +508,13 @@ mod _x128 { } // Float - from_float! { - f32, u32 => i128; - f64, u64 => i128, u128; + from_float_dst! { + f32 => u128; } - from_float_dst! { - f32 => u128; + from_float! { + f32 => i128; + f64 => i128, u128; } } |