stratax::core::Slice Class Reference

Describes a signed, strided half-open index range. More...

#include <Slice.hpp>

Public Types
using	size_type = std::size_t
	Unsigned type used for the number of selected indices.
using	difference_type = std::ptrdiff_t
	Signed type used for bounds and step values.

Public Member Functions
	Slice (difference_type start, difference_type stop, difference_type step=1)
	Constructs a slice from raw half-open bounds and a step.
difference_type	start () const noexcept
	Returns the raw inclusive start bound.
difference_type	stop () const noexcept
	Returns the raw exclusive stop bound.
difference_type	step () const noexcept
	Returns the nonzero signed step.
size_type	size () const noexcept
	Returns the number of indices described by the raw range.
bool	empty () const noexcept
	Reports whether the raw range selects no indices.
bool	operator== (const Slice &other) const noexcept
	Compares two slices by their stored bounds and step.

Detailed Description

Describes a signed, strided half-open index range.

Slice stores raw [start, stop) bounds and a nonzero step. A positive step selects values while they are less than stop; a negative step selects values while they are greater than stop. Bounds are not normalized or clamped by this class because normalization depends on the dimension being sliced.

Example

const stratax::core::Slice forward{1, 8, 2};
// Selects 1, 3, 5, 7; forward.size() == 4.
 
const stratax::core::Slice reverse{7, 0, -2};
// Selects 7, 5, 3, 1; reverse.size() == 4.

See also

stratax::indexing::slice

Definition at line 30 of file Slice.hpp.

Member Typedef Documentation

difference_type

using stratax::core::Slice::difference_type = std::ptrdiff_t

Signed type used for bounds and step values.

Definition at line 36 of file Slice.hpp.

size_type

using stratax::core::Slice::size_type = std::size_t

Unsigned type used for the number of selected indices.

Definition at line 34 of file Slice.hpp.

Constructor & Destructor Documentation

Slice()

stratax::core::Slice::Slice ( difference_type  start, difference_type  stop, difference_type  step = 1  )

inline

Constructs a slice from raw half-open bounds and a step.

The values are stored unchanged. In particular, negative bounds are not converted relative to a container extent during construction.

Parameters

start	First index in the range when the range is non-empty.
stop	Exclusive boundary that terminates the range.
step	Nonzero increment between consecutive indices.

Exceptions

Exceptions::IndexError

If step is zero.

Complexity

O(1).

Definition at line 56 of file Slice.hpp.

Member Function Documentation

empty()

bool stratax::core::Slice::empty ( ) const

inlinenoexcept

Reports whether the raw range selects no indices.

Complexity

O(1).

Definition at line 111 of file Slice.hpp.

operator==()

bool stratax::core::Slice::operator== ( const Slice &  other ) const

inlinenoexcept

Compares two slices by their stored bounds and step.

Parameters

other

Slice to compare with this slice.

Returns

true when start, stop, and step are all equal.

Complexity

O(1).

Definition at line 119 of file Slice.hpp.

size()

size_type stratax::core::Slice::size ( ) const

inlinenoexcept

Returns the number of indices described by the raw range.

A positive-step slice is empty when start() >= stop(). A negative-step slice is empty when start() <= stop(). Otherwise the result is the ceiling of the directed distance divided by the absolute step.

This calculation does not normalize bounds against a container extent.

Returns

Number of generated indices.

Precondition

Intermediate signed distance and rounding arithmetic must be representable by difference_type.

Complexity

O(1).

Definition at line 87 of file Slice.hpp.

start()

difference_type stratax::core::Slice::start ( ) const

inlinenoexcept

Returns the raw inclusive start bound.

Complexity

O(1).

Definition at line 67 of file Slice.hpp.

step()

difference_type stratax::core::Slice::step ( ) const

inlinenoexcept

Returns the nonzero signed step.

Complexity

O(1).

Definition at line 71 of file Slice.hpp.

stop()

difference_type stratax::core::Slice::stop ( ) const

inlinenoexcept

Returns the raw exclusive stop bound.

Complexity

O(1).

Definition at line 69 of file Slice.hpp.

---

The documentation for this class was generated from the following file:

• include/stratax/core/Slice.hpp