fn __rust_alloc_error_handler(size: usize, align: usize) -> !;
}
-/// Abort on memory allocation error or failure.
+/// Signal a memory allocation error.
///
-/// Callers of memory allocation APIs wishing to abort computation
+/// Callers of memory allocation APIs wishing to cease execution
/// in response to an allocation error are encouraged to call this function,
-/// rather than directly invoking `panic!` or similar.
+/// rather than directly invoking [`panic!`] or similar.
///
-/// The default behavior of this function is to print a message to standard error
-/// and abort the process.
-/// It can be replaced with [`set_alloc_error_hook`] and [`take_alloc_error_hook`].
+/// This function is guaranteed to diverge (not return normally with a value), but depending on
+/// global configuration, it may either panic (resulting in unwinding or aborting as per
+/// configuration for all panics), or abort the process (with no unwinding).
+///
+/// The default behavior is:
+///
+/// * If the binary links against `std` (typically the case), then
+/// print a message to standard error and abort the process.
+/// This behavior can be replaced with [`set_alloc_error_hook`] and [`take_alloc_error_hook`].
+/// Future versions of Rust may panic by default instead.
+///
+/// * If the binary does not link against `std` (all of its crates are marked
+/// [`#![no_std]`][no_std]), then call [`panic!`] with a message.
+/// [The panic handler] applies as to any panic.
///
/// [`set_alloc_error_hook`]: ../../std/alloc/fn.set_alloc_error_hook.html
/// [`take_alloc_error_hook`]: ../../std/alloc/fn.take_alloc_error_hook.html
+/// [The panic handler]: https://doc.rust-lang.org/reference/runtime.html#the-panic_handler-attribute
+/// [no_std]: https://doc.rust-lang.org/reference/names/preludes.html#the-no_std-attribute
#[stable(feature = "global_alloc", since = "1.28.0")]
#[rustc_const_unstable(feature = "const_alloc_error", issue = "92523")]
#[cfg(all(not(no_global_oom_handling), not(test)))]
if unsafe { __rust_alloc_error_handler_should_panic != 0 } {
panic!("memory allocation of {size} bytes failed")
} else {
- core::panicking::panic_nounwind_fmt(format_args!(
- "memory allocation of {size} bytes failed"
- ))
+ core::panicking::panic_nounwind_fmt(
+ format_args!("memory allocation of {size} bytes failed"),
+ /* force_no_backtrace */ false,
+ )
}
}
}
#![warn(missing_docs)]
#![allow(explicit_outlives_requirements)]
#![warn(multiple_supertrait_upcastable)]
-#![cfg_attr(not(bootstrap), allow(internal_features))]
-#![cfg_attr(not(bootstrap), allow(rustdoc::redundant_explicit_links))]
+#![allow(internal_features)]
+#![allow(rustdoc::redundant_explicit_links)]
//
// Library features:
// tidy-alphabetical-start
#![feature(const_waker)]
#![feature(core_intrinsics)]
#![feature(core_panic)]
+#![feature(deprecated_suggestion)]
#![feature(dispatch_from_dyn)]
#![feature(error_generic_member_access)]
#![feature(error_in_core)]
#![feature(ptr_metadata)]
#![feature(ptr_sub_ptr)]
#![feature(receiver_trait)]
-#![feature(saturating_int_impl)]
#![feature(set_ptr_value)]
#![feature(sized_type_properties)]
#![feature(slice_from_ptr_range)]
/// Shortens the vector, keeping the first `len` elements and dropping
/// the rest.
///
- /// If `len` is greater than the vector's current length, this has no
- /// effect.
+ /// If `len` is greater or equal to the vector's current length, this has
+ /// no effect.
///
/// The [`drain`] method can emulate `truncate`, but causes the excess
/// elements to be returned instead of dropped.
/// is never written to (except inside an `UnsafeCell`) using this pointer or any pointer
/// derived from it. If you need to mutate the contents of the slice, use [`as_mut_ptr`].
///
+ /// This method guarantees that for the purpose of the aliasing model, this method
+ /// does not materialize a reference to the underlying slice, and thus the returned pointer
+ /// will remain valid when mixed with other calls to [`as_ptr`] and [`as_mut_ptr`].
+ /// Note that calling other methods that materialize mutable references to the slice,
+ /// or mutable references to specific elements you are planning on accessing through this pointer,
+ /// as well as writing to those elements, may still invalidate this pointer.
+ /// See the second example below for how this guarantee can be used.
+ ///
+ ///
/// # Examples
///
/// ```
/// }
/// ```
///
+ /// Due to the aliasing guarantee, the following code is legal:
+ ///
+ /// ```rust
+ /// unsafe {
+ /// let mut v = vec![0, 1, 2];
+ /// let ptr1 = v.as_ptr();
+ /// let _ = ptr1.read();
+ /// let ptr2 = v.as_mut_ptr().offset(2);
+ /// ptr2.write(2);
+ /// // Notably, the write to `ptr2` did *not* invalidate `ptr1`
+ /// // because it mutated a different element:
+ /// let _ = ptr1.read();
+ /// }
+ /// ```
+ ///
/// [`as_mut_ptr`]: Vec::as_mut_ptr
+ /// [`as_ptr`]: Vec::as_ptr
#[stable(feature = "vec_as_ptr", since = "1.37.0")]
+ #[cfg_attr(not(bootstrap), rustc_never_returns_null_ptr)]
#[inline]
pub fn as_ptr(&self) -> *const T {
// We shadow the slice method of the same name to avoid going through
/// Modifying the vector may cause its buffer to be reallocated,
/// which would also make any pointers to it invalid.
///
+ /// This method guarantees that for the purpose of the aliasing model, this method
+ /// does not materialize a reference to the underlying slice, and thus the returned pointer
+ /// will remain valid when mixed with other calls to [`as_ptr`] and [`as_mut_ptr`].
+ /// Note that calling other methods that materialize references to the slice,
+ /// or references to specific elements you are planning on accessing through this pointer,
+ /// may still invalidate this pointer.
+ /// See the second example below for how this guarantee can be used.
+ ///
+ ///
/// # Examples
///
/// ```
/// }
/// assert_eq!(&*x, &[0, 1, 2, 3]);
/// ```
+ ///
+ /// Due to the aliasing guarantee, the following code is legal:
+ ///
+ /// ```rust
+ /// unsafe {
+ /// let mut v = vec![0];
+ /// let ptr1 = v.as_mut_ptr();
+ /// ptr1.write(1);
+ /// let ptr2 = v.as_mut_ptr();
+ /// ptr2.write(2);
+ /// // Notably, the write to `ptr2` did *not* invalidate `ptr1`:
+ /// ptr1.write(3);
+ /// }
+ /// ```
+ ///
+ /// [`as_mut_ptr`]: Vec::as_mut_ptr
+ /// [`as_ptr`]: Vec::as_ptr
#[stable(feature = "vec_as_ptr", since = "1.37.0")]
+ #[cfg_attr(not(bootstrap), rustc_never_returns_null_ptr)]
#[inline]
pub fn as_mut_ptr(&mut self) -> *mut T {
// We shadow the slice method of the same name to avoid going through
}
}
+#[cfg(not(no_global_oom_handling))]
+#[stable(feature = "vec_from_array_ref", since = "1.74.0")]
+impl<T: Clone, const N: usize> From<&[T; N]> for Vec<T> {
+ /// Allocate a `Vec<T>` and fill it by cloning `s`'s items.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// assert_eq!(Vec::from(&[1, 2, 3]), vec![1, 2, 3]);
+ /// ```
+ fn from(s: &[T; N]) -> Vec<T> {
+ Self::from(s.as_slice())
+ }
+}
+
+#[cfg(not(no_global_oom_handling))]
+#[stable(feature = "vec_from_array_ref", since = "1.74.0")]
+impl<T: Clone, const N: usize> From<&mut [T; N]> for Vec<T> {
+ /// Allocate a `Vec<T>` and fill it by cloning `s`'s items.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// assert_eq!(Vec::from(&mut [1, 2, 3]), vec![1, 2, 3]);
+ /// ```
+ fn from(s: &mut [T; N]) -> Vec<T> {
+ Self::from(s.as_mut_slice())
+ }
+}
+
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "vec_from_array", since = "1.44.0")]
impl<T, const N: usize> From<[T; N]> for Vec<T> {
projects / linux.git / commitdiff