Trait rustc_std_workspace_alloc::slice::SliceIndex
1.28.0 · source · pub unsafe trait SliceIndex<T>: Sealedwhere
T: ?Sized,{
type Output: ?Sized;
// Required methods
fn get(self, slice: &T) -> Option<&Self::Output>;
fn get_mut(self, slice: &mut T) -> Option<&mut Self::Output>;
unsafe fn get_unchecked(self, slice: *const T) -> *const Self::Output;
unsafe fn get_unchecked_mut(self, slice: *mut T) -> *mut Self::Output;
fn index(self, slice: &T) -> &Self::Output;
fn index_mut(self, slice: &mut T) -> &mut Self::Output;
}Expand description
A helper trait used for indexing operations.
Implementations of this trait have to promise that if the argument
to get_unchecked(_mut) is a safe reference, then so is the result.
Required Associated Types§
Required Methods§
sourcefn get(self, slice: &T) -> Option<&Self::Output>
fn get(self, slice: &T) -> Option<&Self::Output>
slice_index_methods)Returns a shared reference to the output at this location, if in bounds.
sourcefn get_mut(self, slice: &mut T) -> Option<&mut Self::Output>
fn get_mut(self, slice: &mut T) -> Option<&mut Self::Output>
slice_index_methods)Returns a mutable reference to the output at this location, if in bounds.
sourceunsafe fn get_unchecked(self, slice: *const T) -> *const Self::Output
unsafe fn get_unchecked(self, slice: *const T) -> *const Self::Output
slice_index_methods)Returns a shared reference to the output at this location, without
performing any bounds checking.
Calling this method with an out-of-bounds index or a dangling slice pointer
is undefined behavior even if the resulting reference is not used.
sourceunsafe fn get_unchecked_mut(self, slice: *mut T) -> *mut Self::Output
unsafe fn get_unchecked_mut(self, slice: *mut T) -> *mut Self::Output
slice_index_methods)Returns a mutable reference to the output at this location, without
performing any bounds checking.
Calling this method with an out-of-bounds index or a dangling slice pointer
is undefined behavior even if the resulting reference is not used.
Implementors§
1.20.0 (const: unstable) · source§impl SliceIndex<str> for Range<usize>
impl SliceIndex<str> for Range<usize>
Implements substring slicing with syntax &self[begin .. end] or &mut self[begin .. end].
Returns a slice of the given string from the byte range
[begin, end).
This operation is O(1).
Prior to 1.20.0, these indexing operations were still supported by
direct implementation of Index and IndexMut.
Panics
Panics if begin or end does not point to the starting byte offset of
a character (as defined by is_char_boundary), if begin > end, or if
end > len.
Examples
let s = "Löwe 老虎 Léopard";
assert_eq!(&s[0 .. 1], "L");
assert_eq!(&s[1 .. 9], "öwe 老");
// these will panic:
// byte 2 lies within `ö`:
// &s[2 ..3];
// byte 8 lies within `老`
// &s[1 .. 8];
// byte 100 is outside the string
// &s[3 .. 100];1.20.0 (const: unstable) · source§impl SliceIndex<str> for RangeFrom<usize>
impl SliceIndex<str> for RangeFrom<usize>
Implements substring slicing with syntax &self[begin ..] or &mut self[begin ..].
Returns a slice of the given string from the byte range [begin, len).
Equivalent to &self[begin .. len] or &mut self[begin .. len].
This operation is O(1).
Prior to 1.20.0, these indexing operations were still supported by
direct implementation of Index and IndexMut.
Panics
Panics if begin does not point to the starting byte offset of
a character (as defined by is_char_boundary), or if begin > len.
1.20.0 (const: unstable) · source§impl SliceIndex<str> for RangeFull
impl SliceIndex<str> for RangeFull
Implements substring slicing with syntax &self[..] or &mut self[..].
Returns a slice of the whole string, i.e., returns &self or &mut self. Equivalent to &self[0 .. len] or &mut self[0 .. len]. Unlike
other indexing operations, this can never panic.
This operation is O(1).
Prior to 1.20.0, these indexing operations were still supported by
direct implementation of Index and IndexMut.
Equivalent to &self[0 .. len] or &mut self[0 .. len].
1.26.0 (const: unstable) · source§impl SliceIndex<str> for RangeInclusive<usize>
impl SliceIndex<str> for RangeInclusive<usize>
Implements substring slicing with syntax &self[begin ..= end] or &mut self[begin ..= end].
Returns a slice of the given string from the byte range
[begin, end]. Equivalent to &self [begin .. end + 1] or &mut self[begin .. end + 1], except if end has the maximum value for
usize.
This operation is O(1).
Panics
Panics if begin does not point to the starting byte offset of
a character (as defined by is_char_boundary), if end does not point
to the ending byte offset of a character (end + 1 is either a starting
byte offset or equal to len), if begin > end, or if end >= len.
1.20.0 (const: unstable) · source§impl SliceIndex<str> for RangeTo<usize>
impl SliceIndex<str> for RangeTo<usize>
Implements substring slicing with syntax &self[.. end] or &mut self[.. end].
Returns a slice of the given string from the byte range [0, end).
Equivalent to &self[0 .. end] or &mut self[0 .. end].
This operation is O(1).
Prior to 1.20.0, these indexing operations were still supported by
direct implementation of Index and IndexMut.
Panics
Panics if end does not point to the starting byte offset of a
character (as defined by is_char_boundary), or if end > len.
1.26.0 (const: unstable) · source§impl SliceIndex<str> for RangeToInclusive<usize>
impl SliceIndex<str> for RangeToInclusive<usize>
Implements substring slicing with syntax &self[..= end] or &mut self[..= end].
Returns a slice of the given string from the byte range [0, end].
Equivalent to &self [0 .. end + 1], except if end has the maximum
value for usize.
This operation is O(1).
Panics
Panics if end does not point to the ending byte offset of a character
(end + 1 is either a starting byte offset as defined by
is_char_boundary, or equal to len), or if end >= len.