Auto merge of #31479 - kamalmarhubi:fmt-pointer-unsized, r=alexcrichton

This allows printing pointers to unsized types with the {:p} formatting
directive. The following impls are extended to unsized types:
 - impl<'a, T: ?Sized> Pointer for &'a T
 - impl<'a, T: ?Sized> Pointer for &'a mut T
 - impl<T: ?Sized> Pointer for *const T
 - impl<T: ?Sized> Pointer for *mut T
 - impl<T: ?Sized> fmt::Pointer for Box<T>
 - impl<T: ?Sized> fmt::Pointer for Rc<T>
 - impl<T: ?Sized> fmt::Pointer for Arc<T>
This commit is contained in:
bors 2016-02-11 01:54:15 +00:00
commit 106070b905
5 changed files with 16 additions and 8 deletions

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@ -879,7 +879,7 @@ impl<T: ?Sized + fmt::Debug> fmt::Debug for Arc<T> {
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> fmt::Pointer for Arc<T> {
impl<T: ?Sized> fmt::Pointer for Arc<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Pointer::fmt(&*self._ptr, f)
}

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@ -442,7 +442,7 @@ impl<T: fmt::Debug + ?Sized> fmt::Debug for Box<T> {
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> fmt::Pointer for Box<T> {
impl<T: ?Sized> fmt::Pointer for Box<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
// It's not possible to extract the inner Uniq directly from the Box,
// instead we cast it to a *const which aliases the Unique

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@ -688,7 +688,7 @@ impl<T: ?Sized + fmt::Debug> fmt::Debug for Rc<T> {
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> fmt::Pointer for Rc<T> {
impl<T: ?Sized> fmt::Pointer for Rc<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Pointer::fmt(&*self._ptr, f)
}

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@ -1384,7 +1384,7 @@ impl Display for char {
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> Pointer for *const T {
impl<T: ?Sized> Pointer for *const T {
fn fmt(&self, f: &mut Formatter) -> Result {
let old_width = f.width;
let old_flags = f.flags;
@ -1402,7 +1402,7 @@ impl<T> Pointer for *const T {
}
f.flags |= 1 << (FlagV1::Alternate as u32);
let ret = LowerHex::fmt(&(*self as usize), f);
let ret = LowerHex::fmt(&(*self as *const () as usize), f);
f.width = old_width;
f.flags = old_flags;
@ -1412,21 +1412,21 @@ impl<T> Pointer for *const T {
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> Pointer for *mut T {
impl<T: ?Sized> Pointer for *mut T {
fn fmt(&self, f: &mut Formatter) -> Result {
Pointer::fmt(&(*self as *const T), f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> Pointer for &'a T {
impl<'a, T: ?Sized> Pointer for &'a T {
fn fmt(&self, f: &mut Formatter) -> Result {
Pointer::fmt(&(*self as *const T), f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> Pointer for &'a mut T {
impl<'a, T: ?Sized> Pointer for &'a mut T {
fn fmt(&self, f: &mut Formatter) -> Result {
Pointer::fmt(&(&**self as *const T), f)
}

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@ -20,3 +20,11 @@ fn test_format_flags() {
assert_eq!(format!("{: >3}", 'a'), " a");
}
#[test]
fn test_pointer_formats_data_pointer() {
let b: &[u8] = b"";
let s: &str = "";
assert_eq!(format!("{:p}", s), format!("{:p}", s.as_ptr()));
assert_eq!(format!("{:p}", b), format!("{:p}", b.as_ptr()));
}