TRange

Template for ranges.

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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

Public function

TRange()

Default constructor (no initialization).

Public function

TRange

(
    ElementValueOrConstRef A
)

Create a range with a single element.

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

Public function

TRange

(
    ElementValueOrConstRef A,
    ElementValueOrConstRef B
)

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

Public function

TRange

(
    const BoundsType& InLowerBound,
    const BoundsType& InUpperBound
)

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

Functions

Name Description

Public function Const

bool

 

Adjoins

(
    const TRange& Other
)

Check whether this range adjoins to another.

Public function Static

TRange

 

All()

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

Public function Static

TRange

 

AtLeast

(
    ElementValueOrConstRef Value
)

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

Public function Static

TRange

 

AtMost

(
    ElementValueOrConstRef Value
)

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

Public function Const

bool

 

Conjoins

(
    const TRange& X,
    const TRange& Y
)

Check whether this range conjoins the two given ranges.

Public function Const

bool

 

Contains

(
    const TRange& Other
)

Check whether this range contains another range.

Public function Const

bool

 

Contains

(
    ElementValueOrConstRef Element
)

Check whether this range contains the specified element.

Public function Const

bool

 

Contiguous

(
    const TRange& Other
)

Check if this range is contiguous with another range.

Public function Static

TArray< TRan...

 

Difference

(
    const TRange& X,
    const TRange& Y
)

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

Public function Static

TRange

 

Empty()

Return an empty range.

Public function Static

TRange

 

Exclusive

(
    ElementValueOrConstRef Min,
    ElementValueOrConstRef Max
)

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

Public function Const

BoundsType

 

GetLowerBound()

Get the range's lower bound.

Public function Const

ElementValue...

 

GetLowerBoundValue()

Get the value of the lower bound.

Public function Const

BoundsType

 

GetUpperBound()

Get the range's upper bound.

Public function Const

ElementValue...

 

GetUpperBoundValue()

Get the value of the upper bound.

Public function Static

TRange

 

GreaterThan

(
    ElementValueOrConstRef Value
)

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

Public function Const

bool

 

HasLowerBound()

Check whether the range has a lower bound.

Public function Const

bool

 

HasUpperBound()

Check whether the range has an upper bound.

Public function Static

TRange

 

Hull

(
    const TRange& X,
    const TRange& Y
)

Compute the hull of two ranges.

The hull is the smallest range that contains both ranges.

Public function Static

TRange

 

Hull

(
    const TArray< TRange >& Ranges
)

Compute the hull of many ranges.

Public function Static

TRange

 

Inclusive

(
    ElementValueOrConstRef Min,
    ElementValueOrConstRef Max
)

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

Public function Static

TRange

 

Intersection

(
    const TRange& X,
    const TRange& Y
)

Compute the intersection of two ranges.

Public function Static

TRange

 

Intersection

(
    const TArray< TRange >& Ranges
)

Compute the intersection of many ranges.

Public function Const

bool

 

IsDegenerate()

Check whether this range is degenerate.

Public function Const

bool

 

IsEmpty()

Check whether this range is empty.

Public function Static

TRange

 

LessThan

(
    ElementValueOrConstRef Value
)

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

Public function Const

bool

 

Overlaps

(
    const TRange& Other
)

Check whether this range overlaps with another.

Public function

void

 

SetLowerBound

(
    const BoundsType& NewLowerBound
)

Assign the new lower bound for this range

Public function

void

 

SetLowerBoundValue

(
    ElementValueOrConstRef NewLowerBoun...
)

Assign the new lower bound value for this range.

Public function

void

 

SetUpperBound

(
    const BoundsType& NewUpperBound
)

Assign the new upper bound for this range

Public function

void

 

SetUpperBoundValue

(
    ElementValueOrConstRef NewUpperBoun...
)

Assign the new upper bound value for this range.

Public function Const

DifferenceTy...

 

Size()

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

Public function Const

TArray< TRan...

 

Split

(
    ElementValueOrConstRef Element
)

Split the range into two ranges at the specified element.

Public function Static

TArray< TRan...

 

Union

(
    const TRange& X,
    const TRange& Y
)

Return the union of two contiguous ranges.

Operators

Name Description

Public function Const

bool

 

operator!=

(
    const TRange& Other
)

Compare this range with the specified range for inequality.

Public function Const

bool

 

operator==

(
    const TRange& Other
)

Compare this range with the specified range for equality.

Typedefs

See Also

RangeBound

TInterval