bjoernager/rust
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Replace unnecessary uses of TraitObject with casts

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This commit is contained in:
Andrew Paseltiner 2016-08-25 20:56:47 -04:00
parent eaf71f8d10
commit 2b10df7f24
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GPG key ID: DA5CDC15F9BEDB2B
4 changed files with 9 additions and 38 deletions
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9
src/liballoc/boxed.rs
View file

@ -67,7 +67,6 @@ use core::mem;
use core::ops::{CoerceUnsized, Deref, DerefMut};
use core::ops::{BoxPlace, Boxed, InPlace, Place, Placer};
use core::ptr::{self, Unique};
use core::raw::TraitObject;
use core::convert::From;
/// A value that represents the heap. This is the default place that the `box`
@ -428,12 +427,8 @@ impl Box<Any> {
pub fn downcast<T: Any>(self) -> Result<Box<T>, Box<Any>> {
if self.is::<T>() {
unsafe {
// Get the raw representation of the trait object
let raw = Box::into_raw(self);
let to: TraitObject = mem::transmute::<*mut Any, TraitObject>(raw);
// Extract the data pointer
Ok(Box::from_raw(to.data as *mut T))
let raw: *mut Any = Box::into_raw(self);
Ok(Box::from_raw(raw as *mut T))
}
} else {
Err(self)

2
src/liballoc/lib.rs
View file

@ -91,7 +91,7 @@
#![cfg_attr(stage0, feature(unsafe_no_drop_flag))]
#![feature(unsize)]
#![cfg_attr(not(test), feature(fused, raw, fn_traits, placement_new_protocol))]
#![cfg_attr(not(test), feature(fused, fn_traits, placement_new_protocol))]
#![cfg_attr(test, feature(test, box_heap))]
// Allow testing this library

14
src/libcore/any.rs
View file

@ -72,8 +72,6 @@
#![stable(feature = "rust1", since = "1.0.0")]
use fmt;
use mem::transmute;
use raw::TraitObject;
use intrinsics;
use marker::Reflect;
@ -199,11 +197,7 @@ impl Any {
pub fn downcast_ref<T: Any>(&self) -> Option<&T> {
if self.is::<T>() {
unsafe {
// Get the raw representation of the trait object
let to: TraitObject = transmute(self);
// Extract the data pointer
Some(&*(to.data as *const T))
Some(&*(self as *const Any as *const T))
}
} else {
None
@ -240,11 +234,7 @@ impl Any {
pub fn downcast_mut<T: Any>(&mut self) -> Option<&mut T> {
if self.is::<T>() {
unsafe {
// Get the raw representation of the trait object
let to: TraitObject = transmute(self);
// Extract the data pointer
Some(&mut *(to.data as *const T as *mut T))
Some(&mut *(self as *mut Any as *mut T))
}
} else {
None

22
src/libstd/error.rs
View file

@ -54,7 +54,6 @@ use fmt::{self, Debug, Display};
use marker::Reflect;
use mem::transmute;
use num;
use raw::TraitObject;
use str;
use string;
@ -326,11 +325,7 @@ impl Error + 'static {
pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> {
if self.is::<T>() {
unsafe {
// Get the raw representation of the trait object
let to: TraitObject = transmute(self);
// Extract the data pointer
Some(&*(to.data as *const T))
Some(&*(self as *const Error as *const T))
}
} else {
None
@ -344,11 +339,7 @@ impl Error + 'static {
pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> {
if self.is::<T>() {
unsafe {
// Get the raw representation of the trait object
let to: TraitObject = transmute(self);
// Extract the data pointer
Some(&mut *(to.data as *const T as *mut T))
Some(&mut *(self as *mut Error as *mut T))
}
} else {
None
@ -409,13 +400,8 @@ impl Error {
pub fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Error>> {
if self.is::<T>() {
unsafe {
// Get the raw representation of the trait object
let raw = Box::into_raw(self);
let to: TraitObject =
transmute::<*mut Error, TraitObject>(raw);
// Extract the data pointer
Ok(Box::from_raw(to.data as *mut T))
let raw: *mut Error = Box::into_raw(self);
Ok(Box::from_raw(raw as *mut T))
}
} else {
Err(self)