TRange

Template for ranges.

Inheritance Hierarchy

References

 Module Core Header /Engine/Source/Runtime/Core/Public/Math/Range.h Include #include "Math/Range.h"

Syntax

template<typename ElementType>
class TRange

Remarks

Template for ranges.

This class is not intended for interval arithmetic (see TInterval for that). A range represents a contiguous set of elements that only stores the set's lower and upper bound values (aka. endpoints) for storage efficiency. Bound values may be exclusive (the value is not part of the range), inclusive (the value is part of the range) or open (there is no limit on the values).

The template's primary focus is on continuous ranges, but it can be used for the representation of discrete ranges as well. The element type of discrete ranges has a well-defined stepping, such as an integer or a date, that separates the neighboring elements. This is in contrast with continuous ranges in which the step sizes, such as floats or time spans, are not of interest, and other elements may be found between any two elements (although, in practice, all ranges are discrete due to the limited precision of numerical values in computers).

When working with ranges, the user of this template is responsible for correctly interpreting the range endpoints. Certain semantics will be different depending on whether the range is interpreted in a continuous or discrete domain.

Iteration of a discrete range [A, B) includes the elements A to B-1. The elements of continuous ranges are generally not meant to be iterated. It is also important to consider the equivalence of different representations of discrete ranges. For example, the ranges [2, 6), (1, 5] and [2, 5] are equivalent in discrete domains, but different in continuous ones. In order to keep this class simple, we have not included canonicalization functions or auxiliary template parameters, such as unit and min/max domain elements. For ease of use in most common use cases, it is recommended to limit all operations to canonical ranges of the form [A, B) in which the lower bound is included and the upper bound is excluded from the range.

Constructors

Name Description

TRange()

Default constructor (no initialization).

TRange

Create a range with a single element.

The created range is of the form [A, A].

TRange

Create and initializes a new range with the given lower and upper bounds.

TRange

(
const BoundsType& InLowerBound,
const BoundsType& InUpperBound
)

Create and initializes a new range with the given lower and upper bounds.

Functions

Name Description

bool

(
const TRange& Other
)

Check whether this range adjoins to another.

TRange

All()

Create an unbounded (open) range that contains all elements of the domain.

TRange

AtLeast

(
ElementValueOrConstRef Value
)

Create a left-bounded range that contains all elements greater than or equal to the specified value.

TRange

AtMost

(
ElementValueOrConstRef Value
)

Create a right-bounded range that contains all elements less than or equal to the specified value.

bool

Conjoins

(
const TRange& X,
const TRange& Y
)

Check whether this range conjoins the two given ranges.

bool

Contains

(
const TRange& Other
)

Check whether this range contains another range.

bool

Contains

(
ElementValueOrConstRef Element
)

Check whether this range contains the specified element.

bool

Contiguous

(
const TRange& Other
)

Check if this range is contiguous with another range.

TArray< TRan...

Difference

(
const TRange& X,
const TRange& Y
)

Calculate the difference between two ranges, i.e. X - Y.

TRange

Empty()

Return an empty range.

TRange

Exclusive

Create a range that excludes the given minimum and maximum values.

BoundsType

GetLowerBound()

Get the range's lower bound.

ElementValue...

GetLowerBoundValue()

Get the value of the lower bound.

BoundsType

GetUpperBound()

Get the range's upper bound.

ElementValue...

GetUpperBoundValue()

Get the value of the upper bound.

TRange

GreaterThan

(
ElementValueOrConstRef Value
)

Create a left-bounded range that contains all elements greater than the specified value.

bool

HasLowerBound()

Check whether the range has a lower bound.

bool

HasUpperBound()

Check whether the range has an upper bound.

TRange

Hull

(
const TRange& X,
const TRange& Y
)

Compute the hull of two ranges.

The hull is the smallest range that contains both ranges.

TRange

Hull

(
const TArray< TRange >& Ranges
)

Compute the hull of many ranges.

TRange

Inclusive

Create a range that includes the given minimum and maximum values.

TRange

Intersection

(
const TRange& X,
const TRange& Y
)

Compute the intersection of two ranges.

TRange

Intersection

(
const TArray< TRange >& Ranges
)

Compute the intersection of many ranges.

bool

IsDegenerate()

Check whether this range is degenerate.

bool

IsEmpty()

Check whether this range is empty.

TRange

LessThan

(
ElementValueOrConstRef Value
)

Create a right-bounded range that contains all elements less than the specified value.

bool

Overlaps

(
const TRange& Other
)

Check whether this range overlaps with another.

void

SetLowerBound

(
const BoundsType& NewLowerBound
)

Assign the new lower bound for this range

void

SetLowerBoundValue

(
ElementValueOrConstRef NewLowerBoun...
)

Assign the new lower bound value for this range.

void

SetUpperBound

(
const BoundsType& NewUpperBound
)

Assign the new upper bound for this range

void

SetUpperBoundValue

(
ElementValueOrConstRef NewUpperBoun...
)

Assign the new upper bound value for this range.

DifferenceTy...

Size()

Compute the size (diameter, length, width) of this range.

TArray< TRan...

Split

(
ElementValueOrConstRef Element
)

Split the range into two ranges at the specified element.

TArray< TRan...

Union

(
const TRange& X,
const TRange& Y
)

Return the union of two contiguous ranges.

Operators

Name Description

bool

operator!=

(
const TRange& Other
)

Compare this range with the specified range for inequality.

bool

operator==

(
const TRange& Other
)

Compare this range with the specified range for equality.

Typedefs