diff options
| -rw-r--r-- | library/alloc/src/vec/mod.rs | 59 | ||||
| -rw-r--r-- | library/alloc/src/vec/spec_from_elem.rs | 60 |
2 files changed, 64 insertions, 55 deletions
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs index a862a979d3b..ae1736d8d3c 100644 --- a/library/alloc/src/vec/mod.rs +++ b/library/alloc/src/vec/mod.rs @@ -105,6 +105,10 @@ mod source_iter_marker; mod partial_eq; +use self::spec_from_elem::SpecFromElem; + +mod spec_from_elem; + /// A contiguous growable array type, written `Vec<T>` but pronounced 'vector'. /// /// # Examples @@ -1995,61 +1999,6 @@ pub fn from_elem_in<T: Clone, A: Allocator>(elem: T, n: usize, alloc: A) -> Vec< <T as SpecFromElem>::from_elem(elem, n, alloc) } -// Specialization trait used for Vec::from_elem -trait SpecFromElem: Sized { - fn from_elem<A: Allocator>(elem: Self, n: usize, alloc: A) -> Vec<Self, A>; -} - -impl<T: Clone> SpecFromElem for T { - default fn from_elem<A: Allocator>(elem: Self, n: usize, alloc: A) -> Vec<Self, A> { - let mut v = Vec::with_capacity_in(n, alloc); - v.extend_with(n, ExtendElement(elem)); - v - } -} - -impl SpecFromElem for i8 { - #[inline] - fn from_elem<A: Allocator>(elem: i8, n: usize, alloc: A) -> Vec<i8, A> { - if elem == 0 { - return Vec { buf: RawVec::with_capacity_zeroed_in(n, alloc), len: n }; - } - unsafe { - let mut v = Vec::with_capacity_in(n, alloc); - ptr::write_bytes(v.as_mut_ptr(), elem as u8, n); - v.set_len(n); - v - } - } -} - -impl SpecFromElem for u8 { - #[inline] - fn from_elem<A: Allocator>(elem: u8, n: usize, alloc: A) -> Vec<u8, A> { - if elem == 0 { - return Vec { buf: RawVec::with_capacity_zeroed_in(n, alloc), len: n }; - } - unsafe { - let mut v = Vec::with_capacity_in(n, alloc); - ptr::write_bytes(v.as_mut_ptr(), elem, n); - v.set_len(n); - v - } - } -} - -impl<T: Clone + IsZero> SpecFromElem for T { - #[inline] - fn from_elem<A: Allocator>(elem: T, n: usize, alloc: A) -> Vec<T, A> { - if elem.is_zero() { - return Vec { buf: RawVec::with_capacity_zeroed_in(n, alloc), len: n }; - } - let mut v = Vec::with_capacity_in(n, alloc); - v.extend_with(n, ExtendElement(elem)); - v - } -} - //////////////////////////////////////////////////////////////////////////////// // Common trait implementations for Vec //////////////////////////////////////////////////////////////////////////////// diff --git a/library/alloc/src/vec/spec_from_elem.rs b/library/alloc/src/vec/spec_from_elem.rs new file mode 100644 index 00000000000..ef89054ea13 --- /dev/null +++ b/library/alloc/src/vec/spec_from_elem.rs @@ -0,0 +1,60 @@ +use crate::alloc::{Allocator}; +use crate::raw_vec::RawVec; +use core::ptr::{self}; + +use super::{Vec, IsZero, ExtendElement}; + +// Specialization trait used for Vec::from_elem +pub(super) trait SpecFromElem: Sized { + fn from_elem<A: Allocator>(elem: Self, n: usize, alloc: A) -> Vec<Self, A>; +} + +impl<T: Clone> SpecFromElem for T { + default fn from_elem<A: Allocator>(elem: Self, n: usize, alloc: A) -> Vec<Self, A> { + let mut v = Vec::with_capacity_in(n, alloc); + v.extend_with(n, ExtendElement(elem)); + v + } +} + +impl SpecFromElem for i8 { + #[inline] + fn from_elem<A: Allocator>(elem: i8, n: usize, alloc: A) -> Vec<i8, A> { + if elem == 0 { + return Vec { buf: RawVec::with_capacity_zeroed_in(n, alloc), len: n }; + } + unsafe { + let mut v = Vec::with_capacity_in(n, alloc); + ptr::write_bytes(v.as_mut_ptr(), elem as u8, n); + v.set_len(n); + v + } + } +} + +impl SpecFromElem for u8 { + #[inline] + fn from_elem<A: Allocator>(elem: u8, n: usize, alloc: A) -> Vec<u8, A> { + if elem == 0 { + return Vec { buf: RawVec::with_capacity_zeroed_in(n, alloc), len: n }; + } + unsafe { + let mut v = Vec::with_capacity_in(n, alloc); + ptr::write_bytes(v.as_mut_ptr(), elem, n); + v.set_len(n); + v + } + } +} + +impl<T: Clone + IsZero> SpecFromElem for T { + #[inline] + fn from_elem<A: Allocator>(elem: T, n: usize, alloc: A) -> Vec<T, A> { + if elem.is_zero() { + return Vec { buf: RawVec::with_capacity_zeroed_in(n, alloc), len: n }; + } + let mut v = Vec::with_capacity_in(n, alloc); + v.extend_with(n, ExtendElement(elem)); + v + } +} \ No newline at end of file |
