\inmodule QtCore More...

#include <qstringbuilder.h>

Inheritance diagram for QStringBuilder< A, B >:

Collaboration diagram for QStringBuilder< A, B >:

Public Types
typedef Concatenable::ConvertTo	ConvertTo

Public Member Functions
	QStringBuilder (A &&a_, B &&b_)

	QStringBuilder (QStringBuilder &&)=default

	QStringBuilder (const QStringBuilder &)=default

	~QStringBuilder ()=default

	operator ConvertTo () const

qsizetype	size () const

bool	isNull () const

Public Member Functions inherited from QStringBuilderCommon< QStringBuilder< A, B >, QtStringBuilder::ConvertToTypeHelper< QConcatenableEx< A >::ConvertTo, QConcatenableEx< B >::ConvertTo >::ConvertTo >
QtStringBuilder::ConvertToTypeHelper< QConcatenableEx< A >::ConvertTo, QConcatenableEx< B >::ConvertTo >::ConvertTo	toUpper () const

QtStringBuilder::ConvertToTypeHelper< QConcatenableEx< A >::ConvertTo, QConcatenableEx< B >::ConvertTo >::ConvertTo	toLower () const

Public Attributes
A	a

B	b

Friends
class	QByteArray

class	QString

Additional Inherited Members
Protected Member Functions inherited from QStringBuilderCommon< QStringBuilder< A, B >, QtStringBuilder::ConvertToTypeHelper< QConcatenableEx< A >::ConvertTo, QConcatenableEx< B >::ConvertTo >::ConvertTo >
QtStringBuilder::ConvertToTypeHelper< QConcatenableEx< A >::ConvertTo, QConcatenableEx< B >::ConvertTo >::ConvertTo	resolved () const

Detailed Description

template<typename A, typename B>
class QStringBuilder< A, B >

\inmodule QtCore

\reentrant

Since: 4.6

The QStringBuilder class is a template class that provides a facility to build up QStrings and QByteArrays from smaller chunks.

To build a QString by multiple concatenations, QString::operator+() is typically used. This causes {n - 1} allocations when building a string from {n} chunks. The same is true for QByteArray.

QStringBuilder uses expression templates to collect the individual chunks, compute the total size, allocate the required amount of memory for the final string object, and copy the chunks into the allocated memory.

The QStringBuilder class is not to be used explicitly in user code. Instances of the class are created as return values of the operator%() function, acting on objects of the following types:

For building QStrings:

\list

QString, (since 5.10:) QStringView
QChar, QLatin1Char, (since 5.10:) char16_t,
QLatin1StringView,
(since 5.10:) {const char16_t[]} ({u"foo"}),
QByteArray, char, {const char[]}. \endlist

The types in the last list point are only available when QT_NO_CAST_FROM_ASCII is not defined.

For building QByteArrays:

\list

QByteArray, char, {const char[]}. \endlist

Concatenating strings with operator%() generally yields better performance than using QString::operator+() on the same chunks if there are three or more of them, and performs equally well in other cases.

Note: Defining QT_USE_QSTRINGBUILDER at build time (this is the default when building Qt libraries and tools), will make using {'+'} when concatenating strings work the same way as operator%().

See also: QLatin1StringView, QString

Definition at line 79 of file qstringbuilder.h.