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TStringView

A string view is a non-owning view of a range of characters.

API > API/Runtime > API/Runtime/Core

A string view is a non-owning view of a range of characters.

Ensure that the underlying string is valid for the lifetime of the string view.

Be careful when constructing a string view from a temporary. Make a local copy if necessary.

FStringView View = Object->GetPathName(); // Invalid

FString PathName = Object->GetPathName(); // Valid FStringView View = PathName;

void ProcessPath(FStringView Path); // Valid ProcessPath(Object->GetPathName());

A string view is implicitly constructible from null-terminated strings, from contiguous ranges of characters such as FString and TStringBuilder, and from literals such as TEXTVIEW("...").

A string view is cheap to copy and is meant to be passed by value. Avoid passing by reference.

A string view is not guaranteed to represent a null-terminated string.

Log or format a string view using UE_LOG(TEXT("%.*s"), View.Len(), View.GetData());

A string view is a good fit for function parameters where the function has no requirements for how the string is stored. A caller may use FString, FStringView, TStringBuilder, a char array, a null-terminated string, or any other type which can convert to a string view.

The UE::String namespace contains many functions that can operate on string views. Most of these functions can be found in String/___.h in Core.

voidUseString(FStringViewInString);FStringString(TEXT("ABC"));constTCHAR*CString=*String;TStringBuilder<16>StringBuilder;StringBuilder.Append(TEXT("ABC"));UseString(String);UseString(CString);UseString(StringBuilder);UseString(TEXT("ABC"));UseString(TEXTVIEW("ABC"));

   
Name TStringView
Type class
Header File /Engine/Source/Runtime/Core/Public/Containers/StringView.h
Include Path #include "Containers/StringView.h"

Syntax

template<typename CharType>  
class TStringView

Constructors

Name Remarks Include Path Unreal Specifiers

constexpr TStringView ( const CharRangeType& InRange
)

 Construct a view from a contiguous range of characters, such as FString or TStringBuilder. Containers/StringView.h  

TStringView ( const OtherCharType* InData
)

 Construct a view of the null-terminated string pointed to by InData. Containers/StringView.h  

constexpr TStringView ( const CharType* InData,
int32 InSize
)

 Construct a view of InSize characters beginning at InData. Containers/StringView.h  

constexpr TStringView ()

 Construct an empty view. Containers/StringView.h  

constexpr TStringView ( const CharType* InData
)

 Construct a view of the null-terminated string pointed to by InData. Containers/StringView.h  

constexpr TStringView ( const OtherCharType* InData,
int32 InSize
)

 Construct a view of InSize characters beginning at InData. Containers/StringView.h  

Typedefs

Name Type Remarks Include Path
ElementType CharType   Containers/StringView.h
ViewType TStringView< CharType >   Containers/StringView.h

Functions

Public

Name Remarks Include Path Unreal Specifiers

const CharType * begin()

 DO NOT USE DIRECTLY STL-like iterators to enable range-based for loop support. Containers/StringView.h  

int32 Compare ( const OtherCharType* Other,
ESearchCase::Type SearchCase
) const

 Compare this view with a null-terminated string. Containers/StringView.h  

int32 Compare ( TStringView< OtherCharType > Other,
ESearchCase::Type SearchCase
) const

 Compare this view with a string view. Containers/StringView.h  

int32 Compare ( OtherRangeType&& Other,
ESearchCase::Type SearchCase
) const

 Compare this view with a character range. Containers/StringView.h  

bool Contains ( ViewType Search,
ESearchCase::Type SearchCase
) const

 Returns whether this view contains the specified substring. Containers/StringView.h  

int32 CopyString ( CharType* Dest,
int32 CharCount,
int32 Position
) const

 Copy characters from the view into a destination buffer without null termination. Containers/StringView.h  

const CharType * end()

   Containers/StringView.h  

bool EndsWith ( ViewType Suffix,
ESearchCase::Type SearchCase
) const

 Returns whether this view ends with the suffix with optional case sensitivity. Containers/StringView.h  

bool EndsWith ( CharType Suffix
) const

 Returns whether this view ends with the suffix character compared case-sensitively. Containers/StringView.h  

bool Equals ( const OtherCharType* Other,
ESearchCase::Type SearchCase
) const

 Check whether this view is equivalent to a string view. Containers/StringView.h  

bool Equals ( OtherRangeType&& Other,
ESearchCase::Type SearchCase
) const

 Check whether this view is equivalent to a character range. Containers/StringView.h  

int32 Find ( ViewType Search,
int32 StartPosition,
ESearchCase::Type SearchCase
) const

 Search the view for the first occurrence of a search string. Containers/StringView.h  

bool FindChar ( CharType Search,
int32& OutIndex
) const

 Search the view for the first occurrence of a character. Containers/StringView.h  

bool FindLastChar ( CharType Search,
int32& OutIndex
) const

 Search the view for the last occurrence of a character. Containers/StringView.h  

const CharType * GetData()

 Returns a pointer to the start of the view. This is NOT guaranteed to be null-terminated! Containers/StringView.h  

bool IsEmpty()

 Returns whether the string view is empty. Containers/StringView.h  

bool IsValidIndex ( int32 Index
) const

 Tests if index is valid, i.e. greater than or equal to zero, and less than the number of characters in the string view. Containers/StringView.h  

ViewType Left ( int32 CharCount
) const

 Returns the left-most part of the view by taking the given number of characters from the left. Containers/StringView.h  

ViewType LeftChop ( int32 CharCount
) const

 Returns the left-most part of the view by chopping the given number of characters from the right. Containers/StringView.h  

void LeftChopInline ( int32 CharCount
)

 Modifies the view by chopping the given number of characters from the right. Containers/StringView.h  

void LeftInline ( int32 CharCount
)

 Modifies the view to be the given number of characters from the left. Containers/StringView.h  

int32 Len()

 Returns the length of the string view. Containers/StringView.h  

ViewType Mid ( int32 Position,
int32 CharCount
) const

 Returns the middle part of the view by taking up to the given number of characters from the given position. Containers/StringView.h  

void MidInline ( int32 Position,
int32 CharCount
)

 Modifies the view to be the middle part by taking up to the given number of characters from the given position. Containers/StringView.h  

SIZE_T NumBytes()

   Containers/StringView.h  

TReversePointerIterator< const CharType > rbegin()

   Containers/StringView.h  

void RemovePrefix ( int32 CharCount
)

 Modifies the view to remove the given number of characters from the start. Containers/StringView.h  

void RemoveSuffix ( int32 CharCount
)

 Modifies the view to remove the given number of characters from the end. Containers/StringView.h  

TReversePointerIterator< const CharType > rend()

   Containers/StringView.h  

void Reset()

 Resets to an empty view Containers/StringView.h  

ViewType Right ( int32 CharCount
) const

 Returns the right-most part of the view by taking the given number of characters from the right. Containers/StringView.h  

ViewType RightChop ( int32 CharCount
) const

 Returns the right-most part of the view by chopping the given number of characters from the left. Containers/StringView.h  

void RightChopInline ( int32 CharCount
)

 Modifies the view by chopping the given number of characters from the left. Containers/StringView.h  

void RightInline ( int32 CharCount
)

 Modifies the view to be the given number of characters from the right. Containers/StringView.h  

bool StartsWith ( CharType Prefix
) const

 Returns whether this view starts with the prefix character compared case-sensitively. Containers/StringView.h  

bool StartsWith ( ViewType Prefix,
ESearchCase::Type SearchCase
) const

 Returns whether this view starts with the prefix with optional case sensitivity. Containers/StringView.h  

ViewType SubStr ( int32 Position,
int32 CharCount
) const

 Alias for Mid. Containers/StringView.h  

ViewType TrimEnd()

 Returns the left part of the view before any whitespace at the end. Containers/StringView.h  

void TrimEndInline()

 Modifies the view to be the left part before any whitespace at the end. Containers/StringView.h  

ViewType TrimStart()

 Returns the right part of the view after any whitespace at the start. Containers/StringView.h  

ViewType TrimStartAndEnd()

 Returns the middle part of the view between any whitespace at the start and end. Containers/StringView.h  

void TrimStartAndEndInline()

 Modifies the view to be the middle part between any whitespace at the start and end. Containers/StringView.h  

void TrimStartInline()

 Modifies the view to be the right part after any whitespace at the start. Containers/StringView.h  

Static

Name Remarks Include Path Unreal Specifiers

static bool PrivateEquals ( TStringView Lhs,
TStringView Rhs
)

   Containers/StringView.h  

static bool PrivateEquals ( TStringView Lhs,
const CharType* Rhs
)

   Containers/StringView.h  

static bool PrivateLess ( TStringView Lhs,
TStringView Rhs
)

   Containers/StringView.h  

Operators

Name Remarks Include Path Unreal Specifiers

const CharType & operator[] ( int32 Index
) const

 Access the character at the given index in the view. Containers/StringView.h  

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