std: Second pass stabilization for `ptr` #20042

alexcrichton · 2014-12-19T20:11:05Z

This commit performs a second pass for stabilization over the std::ptr module.
The specific actions taken were:

The RawPtr trait was renamed to PtrExt
The RawMutPtr trait was renamed to PtrMutExt
The module name ptr is now stable.
These functions were all marked #[stable] with no modification:
- null
- null_mut
- swap
- replace
- read
- write
- PtrExt::is_null
- PtrExt::is_not_null
- PtrExt::offset
These functions remain unstable:
- as_ref, as_mut - the return value of an Option is not fully expressive
  as null isn't the only bad value, and it's unclear
  whether we want to commit to these functions at this
  time. The reference/lifetime semantics as written are
  also problematic in how they encourage arbitrary
  lifetimes.
- zero_memory - This function is currently not used at all in the
  distribution, and in general it plays a broader role in the
  "working with unsafe pointers" story. This story is not yet
  fully developed, so at this time the function remains
  unstable for now.
- read_and_zero - This function remains unstable for largely the same
  reasons as zero_memory.
These functions are now all deprecated:
- PtrExt::null - call ptr::null or ptr::null_mut instead.
- PtrExt::to_uint - use an as expression instead.

rust-highfive · 2014-12-19T20:11:08Z

r? @pcwalton

(rust_highfive has picked a reviewer for you, use r? to override)

alexcrichton · 2014-12-19T20:11:10Z

r? @aturon

aturon · 2014-12-19T22:02:26Z

src/libcore/ptr.rs

    }

    #[inline]
+    #[unstable = "return value does not necessarily convey all possible \


Can you change this to say: Option is not clearly the right return type, and we may want to tie the return lifetime to a borrow of the raw pointer.

aturon · 2014-12-19T22:02:39Z

r=me modulo tiny nit

alexcrichton · 2014-12-20T01:02:41Z

deleting r+ for now, I'd like to take some more time to analyze https://github.com/Gankro/raw-rs/blob/master/src/rawptr.rs

Gankra · 2014-12-20T01:10:37Z

CC me

alexcrichton · 2014-12-28T08:27:51Z

Ok, after thinking about this and talking it over with @gankro, I'm thinking the following:

Adding the free-functions as methods on the PtrExt or PtrMutExt trait would be nice, but does lead to duplication. There's also a desire, however, to keep the duplication due to the free-functions allowing for coercion.
Some functions may wish to be renamed, such as copy_memory => copy, set_memory => write_bytes, etc.
Other convenience methods like add and sub for the offset function taking a uint instead of an int.

For now the functionality stabilized here I believe is a subset of the possible future functionality, and I think we can let feedback during the first alpha cycle to drive the rest of what we stabilize in this module.

Does that sound ok @gankro?

re-r? @aturon

aturon · 2014-12-29T17:44:08Z

src/libcore/ptr.rs

-    fn is_not_null(&self) -> bool { !self.is_null() }
+    /// Returns true if the pointer is not equal to the null pointer.
+    #[stable]
+    fn is_not_null(self) -> bool { !self.is_null() }


Can this be dropped in favor of !p.is_null()?

aturon · 2014-12-29T17:52:42Z

r=me modulo nits.

Gankra · 2014-12-29T18:33:25Z

Sounds okay, but the renames are a back-compat issue, no?

aturon · 2014-12-29T18:37:03Z

@gankro

Sounds okay, but the renames are a back-compat issue, no?

Neither are being stabilized here, FWIW.

Gankra · 2014-12-29T18:44:49Z

Not sure if it matters, but they are compiler intrinsics.

This commit performs a second pass for stabilization over the `std::ptr` module. The specific actions taken were: * The `RawPtr` trait was renamed to `PtrExt` * The `RawMutPtr` trait was renamed to `MutPtrExt` * The module name `ptr` is now stable. * These functions were all marked `#[stable]` with no modification: * `null` * `null_mut` * `swap` * `replace` * `read` * `write` * `PtrExt::is_null` * `PtrExt::offset` * These functions remain unstable: * `as_ref`, `as_mut` - the return value of an `Option` is not fully expressive as null isn't the only bad value, and it's unclear whether we want to commit to these functions at this time. The reference/lifetime semantics as written are also problematic in how they encourage arbitrary lifetimes. * `zero_memory` - This function is currently not used at all in the distribution, and in general it plays a broader role in the "working with unsafe pointers" story. This story is not yet fully developed, so at this time the function remains unstable for now. * `read_and_zero` - This function remains unstable for largely the same reasons as `zero_memory`. * These functions are now all deprecated: * `PtrExt::null` - call `ptr::null` or `ptr::null_mut` instead. * `PtrExt::to_uint` - use an `as` expression instead. * `PtrExt::is_not_null` - use `!p.is_null()` instead.

This commit performs a second pass for stabilization over the `std::ptr` module. The specific actions taken were: * The `RawPtr` trait was renamed to `PtrExt` * The `RawMutPtr` trait was renamed to `PtrMutExt` * The module name `ptr` is now stable. * These functions were all marked `#[stable]` with no modification: * `null` * `null_mut` * `swap` * `replace` * `read` * `write` * `PtrExt::is_null` * `PtrExt::is_not_null` * `PtrExt::offset` * These functions remain unstable: * `as_ref`, `as_mut` - the return value of an `Option` is not fully expressive as null isn't the only bad value, and it's unclear whether we want to commit to these functions at this time. The reference/lifetime semantics as written are also problematic in how they encourage arbitrary lifetimes. * `zero_memory` - This function is currently not used at all in the distribution, and in general it plays a broader role in the "working with unsafe pointers" story. This story is not yet fully developed, so at this time the function remains unstable for now. * `read_and_zero` - This function remains unstable for largely the same reasons as `zero_memory`. * These functions are now all deprecated: * `PtrExt::null` - call `ptr::null` or `ptr::null_mut` instead. * `PtrExt::to_uint` - use an `as` expression instead.

rust-highfive assigned pcwalton Dec 19, 2014

rust-highfive assigned aturon and unassigned pcwalton Dec 19, 2014

aturon mentioned this pull request Dec 19, 2014

Stabilization metabug: 1.0-alpha #19260

Closed

alexcrichton force-pushed the second-pass-ptr branch from 84e1ac0 to 3bdbde3 Compare December 19, 2014 21:41

aturon reviewed Dec 19, 2014
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alexcrichton force-pushed the second-pass-ptr branch from 3bdbde3 to ad09584 Compare December 19, 2014 22:04

alexcrichton force-pushed the second-pass-ptr branch from ad09584 to 6ed5017 Compare December 28, 2014 08:24

alexcrichton force-pushed the second-pass-ptr branch from 6ed5017 to 105a2ae Compare December 29, 2014 17:06

aturon reviewed Dec 29, 2014
View reviewed changes

alexcrichton force-pushed the second-pass-ptr branch from 105a2ae to e2f88b8 Compare December 29, 2014 19:24

alexcrichton force-pushed the second-pass-ptr branch from e2f88b8 to 54452cd Compare December 29, 2014 23:58

bors merged commit 54452cd into rust-lang:master Dec 30, 2014

alexcrichton deleted the second-pass-ptr branch January 7, 2015 05:15

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std: Second pass stabilization for `ptr` #20042

std: Second pass stabilization for `ptr` #20042

alexcrichton commented Dec 19, 2014

rust-highfive commented Dec 19, 2014

alexcrichton commented Dec 19, 2014

aturon Dec 19, 2014

aturon commented Dec 19, 2014

alexcrichton commented Dec 20, 2014

Gankra commented Dec 20, 2014

alexcrichton commented Dec 28, 2014

aturon Dec 29, 2014

aturon commented Dec 29, 2014

Gankra commented Dec 29, 2014

aturon commented Dec 29, 2014

Gankra commented Dec 29, 2014

std: Second pass stabilization for ptr #20042

std: Second pass stabilization for ptr #20042

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Gankra commented Dec 29, 2014

std: Second pass stabilization for `ptr` #20042

std: Second pass stabilization for `ptr` #20042