1. Epic GamesDeveloper
  3. TArrayView

TArrayView

Templated fixed-size view of another array

Unreal Engine C++ API Reference > Runtime > Core > Containers

Inheritance Hierarchy

References

   
Module Core
Header /Engine/Source/Runtime/Core/Public/Containers/ArrayView.h
Include #include "Containers/ArrayView.h"

Syntax

template<typename InElementType, typename InSizeType>  
class TArrayView

Remarks

Templated fixed-size view of another array

A statically sized view of an array of typed elements. Designed to allow functions to take either a fixed C array or a TArray with an arbitrary allocator as an argument when the function neither adds nor removes elements

e.g.: int32 SumAll(TArrayView array) { return Algo::Accumulate(array); }

could be called as: SumAll(MyTArray);\ SumAll(MyCArray); SumAll(MakeArrayView(Ptr, Num));

auto Values = { 1, 2, 3 }; SumAll(Values);

Note: View classes are not const-propagating! If you want a view where the elements are const, you need "TArrayView" not "const TArrayView"!

Caution: Treat a view like a reference to the elements in the array. DO NOT free or reallocate the array while the view exists! For this reason, be mindful of lifetimes when constructing TArrayViews from rvalue initializer lists:

TArrayView View = { 1, 2, 3 }; // construction of array view from rvalue initializer list int n = View[0]; // undefined behavior, as the initializer list was destroyed at the end of the previous line

Constructors

  Type Name Description
Public function   Constructor.
Public function  

TArrayView ( OtherRangeType&& Other
)

 Constructor from another range
Public function  

TArrayView ( OtherRangeType&& Other
)

  
Public function  

TArrayView ( std::initializer_list< ElementType > List
)

 Construct a view of an initializer list.
Public function  

TArrayView ( OtherElementType* InData,
SizeType InCount
)

 Construct a view of an arbitrary pointer

Functions

  Type Name Description
Public function Const ElementType *

begin ()

 DO NOT USE DIRECTLY STL-like iterators to enable range-based for loop support.
Public function Const void Checks array invariants: if array size is greater than or equal to zero.
Public function Const bool

Contains ( const ComparisonType& Item
)

 Checks if this array contains the element.
Public function Const bool

ContainsByPredicate ( Predicate Pred
)

 Checks if this array contains an element for which the predicate is true.
Public function Const ElementType *

end ()

  
Public function Const TArray< std::remove_const_t< ElementType > >

FilterByPredicate ( Predicate Pred
)

 Filters the elements in the array based on a predicate functor.
Public function Const bool

Find ( const ElementType& Item,
SizeType& Index
)

 Finds element within the array.
Public function Const SizeType

Find ( const ElementType& Item
)

 Finds element within the array.
Public function Const ElementType *

FindByKey ( const KeyType& Key
)

 Finds an item by key (assuming the ElementType overloads operator== for the comparison).
Public function Const ElementType *

FindByPredicate ( Predicate Pred
)

 Finds an element which matches a predicate functor.
Public function Const bool

FindLast ( const ElementType& Item,
SizeType& Index
)

 Finds element within the array starting from the end.
Public function Const SizeType

FindLastByPredicate ( Predicate Pred
)

 Finds element within the array starting from the end. Uses predicate to match element.
Public function Const SizeType

FindLastByPredicate ( Predicate Pred,
SizeType StartIndex
)

 Finds element within the array starting from StartIndex and going backwards.
Public function Const ElementType *

GetData ()

 Helper function for returning a typed pointer to the first array entry.
Public function Static constexpr size_t Helper function returning the alignment of the inner type.
Public function Static constexpr size_t Helper function returning the size of the inner type.
Public function Const SizeType

IndexOfByKey ( const KeyType& Key
)

 Finds an item by key (assuming the ElementType overloads operator== for the comparison).
Public function Const SizeType

IndexOfByPredicate ( Predicate Pred
)

 Finds an item by predicate.
Public function Const bool

IsEmpty ()

 Returns true if the array view is empty and contains no elements.
Public function Const bool Tests if index is valid, i.e. greater than or equal to zero, and less than the number of elements in the array.
Public function Const ElementType &

Last ( SizeType IndexFromTheEnd
)

 Returns n-th last element from the array.
Public function Const TArrayView

Left ( SizeType Count
)

 Returns the left-most part of the view by taking the given number of elements from the left.
Public function Const TArrayView

LeftChop ( SizeType Count
)

 Returns the left-most part of the view by chopping the given number of elements from the right.
Public function void

LeftChopInline ( SizeType CharCount
)

 Modifies the view by chopping the given number of elements from the right.
Public function void

LeftInline ( SizeType CharCount
)

 Modifies the view to be the given number of elements from the left.
Public function Const TArrayView

Mid ( SizeType Index,
SizeType Count
)

 Returns the middle part of the view by taking up to the given number of elements from the given position.
Public function void

MidInline ( SizeType Position,
SizeType CharCount
)

 Modifies the view to be the middle part by taking up to the given number of elements from the given position.
Public function Const SizeType

Num ()

 Returns number of elements in array.
Public function Const void

RangeCheck ( SizeType Index
)

 Checks if index is in array range.
Public function Const TReversePointerIterator< ElementType >

rbegin ()

  
Public function Const TReversePointerIterator< ElementType >

rend ()

  
Public function Const TArrayView

Right ( SizeType Count
)

 Returns the right-most part of the view by taking the given number of elements from the right.
Public function Const TArrayView

RightChop ( SizeType Count
)

 Returns the right-most part of the view by chopping the given number of elements from the left.
Public function void

RightChopInline ( SizeType CharCount
)

 Modifies the view by chopping the given number of elements from the left.
Public function void

RightInline ( SizeType CharCount
)

 Modifies the view to be the given number of elements from the right.
Public function Const TArrayView

Slice ( SizeType Index,
SizeType InNum
)

 Returns a sliced view This is similar to Mid(), but with a narrow contract, i.e. slicing outside of the range of the view is illegal.
Public function Const void

SliceRangeCheck ( SizeType Index,
SizeType InNum
)

 Checks if a slice range [Index, Index+InNum) is in array range.
Public function void

Sort ()

 Sorts the array assuming < operator is defined for the item type.
Public function void

Sort ( const PREDICATE_CLASS& Predicate
)

 Sorts the array using user define predicate class.
Public function void Stable sorts the array assuming < operator is defined for the item type.
Public function void

StableSort ( const PREDICATE_CLASS& Predicate
)

 Stable sorts the array using user defined predicate class.

Operators

  Type Name Description
Public function Const ElementType &

operator[] ( SizeType Index
)

 Array bracket operator. Returns reference to element at given index.

Typedefs

Name Description
ElementType  
SizeType  
TIsCompatibleElementType  
TIsCompatibleRangeType  
TIsReinterpretableRangeType  

Ask questions and help your peers Developer Forums

Write your own tutorials or read those from others Learning Library

On this page