TStringBuilderBase | Unreal Engine 4.27 Documentation

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

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References


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

Syntax

template<typename CharType>  
class TStringBuilderBase

Remarks

String Builder

This class helps with the common task of constructing new strings.

It does this by allocating buffer space which is used to hold the constructed string. The intent is that the builder is allocated on the stack as a function local variable to avoid heap allocations.

The buffer is always contiguous and the class is not intended to be used to construct extremely large strings.

This is not intended to be used as a mechanism for holding on to strings for a long time. The use case is explicitly to aid in constructing strings on the stack and subsequently passing the string into a function call or a more permanent string storage mechanism like FString et al.

The amount of buffer space to allocate is specified via a template parameter and if the constructed string should overflow this initial buffer, a new buffer will be allocated using regular dynamic memory allocations.

Overflow allocation should be the exceptional case however always try to size the buffer so that it can hold the vast majority of strings you expect to construct.

Be mindful that stack is a limited resource, so if you are writing a highly recursive function you may want to use some other mechanism to build your strings.

Variables

	Type	Name	Description
	CharType *	Base
	bool	bIsDynamic
	CharType *	CurPos
	CharType *	End

Constructors

	Type	Name	Description
		TStringBuilderBase ()
		TStringBuilderBase ( const TStringBuilderBase& )
		TStringBuilderBase ( TStringBuilderBase&& )
		TStringBuilderBase ( CharType* BufferPointer, int32 BufferCapacity )

Destructors

	Type	Name	Description
	CORE_API	~TStringBuilderBase ()

Functions

Type	Name	Description
int32	AddUninitialized ( int32 InCount )	Adds a given number of uninitialized characters into the string builder.
void *	AllocBuffer ( SIZE_T CharCount )
BuilderType &	Append ( const OtherCharType*const String, const int32 Length )
auto	Append ( CharRangeType&& Range )
BuilderType &	AppendChar ( AppendedCharType Char )
BuilderType &	Appendf ( const FmtType& Fmt, Types... Args )	Appends to the string builder similarly to how classic sprintf works.
BuilderType &	AppendV ( const CharType* Fmt, va_list Args )	Appends to the string builder similarly to how classic vsprintf works.
void	EnsureAdditionalCapacity ( int32 RequiredAdditionalCapacity )
void	EnsureNulTerminated ()
void	Extend ( SIZE_T ExtraCapacity )
void	FreeBuffer ( void* Buffer, SIZE_T CharCount )
SIZE_T	GetAllocatedSize ()	Helper function to return the amount of memory allocated by this container.
const CharType *	GetData ()
CharType *	GetData ()	Returns a pointer to Len() code units that are not necessarily null-terminated.
void	Initialize ( CharType* InBase, int32 InCapacity )
void	InsertAt ( int32 Pos, ViewType Str )	Insert substring at given position
BuilderType &	Join ( RangeType&& InRange, DelimiterType&& InDelimiter )	Append every element of the range to the builder, separating the elements by the delimiter.
BuilderType &	JoinQuoted ( RangeType&& InRange, DelimiterType&& InDelimiter, QuoteType&& InQuote )	Append every element of the range to the builder, separating the elements by the delimiter, and surrounding every element on each side with the given quote.
const CharType	LastChar ()	Returns the last character, technically the last code unit.
int32	Len ()
void	Prepend ( ViewType Str )	Insert prefix
void	RemoveAt ( int32 Pos, int32 RemoveLen )	Remove characters at given position
void	RemoveSuffix ( int32 InCount )	Modifies the string builder to remove the given number of characters from the end.
void	ReplaceAt ( int32 Pos, int32 RemoveLen, ViewType Str )	Replace characters at given position and length with substring
void	Reset ()	Empties the string builder, but doesn't change memory allocation.
const CharType *	ToString ()	Returns a pointer to a null-terminated string that is valid until the builder is mutated.
ViewType	ToView ()	Returns a view of the string that is valid until the builder is mutated.

Operators

Type	Name	Description
const CharType *	operator* ()	Returns a pointer to a null-terminated string that is valid until the builder is mutated.
TStringBuilderBase &	operator= ( const TStringBuilderBase& )
TStringBuilderBase &	operator= ( TStringBuilderBase&& )
TStringBuilderBase &	operator= ( ViewType Str )
TStringBuilderBase &	operator= ( const CharType* Str )

Typedefs

Name	Description
BuilderType	The string builder base type to be used by append operators and function output parameters.
ElementType	The character type that this builder operates on.
TIsCharEncodingCompatibleWithCharType
ViewType	The string view type that this builder is compatible with.

Constants

Name	Description
EmptyBuffer
TCanAppend_V	Whether the given type can be appended to this builder using the append operator.
TCanAppendRange_V	Whether the given range type can have its elements appended to the builder using the append operator.

Deprecated Functions

	Type	Name	Description
	BuilderType &	AppendAnsi ( const FAnsiStringView String )	Use Append instead of AppendAnsi.

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