ConstIterator 類

class QCborArray ::ConstIterator

The QCborArray::ConstIterator 類提供 STL 樣式 const 迭代器為 QCborArray . 更多...

該類在 Qt 5.12 引入。

公共類型

typedef iterator_category

公共函數

ConstIterator (const ConstIterator & other )
ConstIterator ()
ConstIterator & operator= (const ConstIterator & other )
bool operator!= (const Iterator & o ) const
bool operator!= (const ConstIterator & o ) const
const QCborValueRef operator* () const
ConstIterator operator+ (qsizetype j ) const
ConstIterator & operator++ ()
ConstIterator operator++ ( int )
ConstIterator & operator+= (qsizetype j )
ConstIterator operator- (qsizetype j ) const
qsizetype operator- (ConstIterator other ) const
ConstIterator & operator-- ()
ConstIterator operator-- ( int )
ConstIterator & operator-= (qsizetype j )
const QCborValueRef * operator-> () const
bool operator< (const Iterator & other ) const
bool operator< (const ConstIterator & other ) const
bool operator<= (const Iterator & other ) const
bool operator<= (const ConstIterator & other ) const
bool operator== (const Iterator & other ) const
bool operator== (const ConstIterator & other ) const
bool operator> (const Iterator & other ) const
bool operator> (const ConstIterator & other ) const
bool operator>= (const Iterator & other ) const
bool operator>= (const ConstIterator & other ) const
const QCborValueRef operator[] (qsizetype j )

詳細描述

QCborArray::ConstIterator allows you to iterate over a QCborArray . If you want to modify the QCborArray as you iterate over it, use QCborArray::Iterator instead. It is generally good practice to use QCborArray::ConstIterator , even on a non-const QCborArray , when you don't need to change the QCborArray through the iterator. Const iterators are slightly faster and improves code readability.

Iterators are initialized by using a QCborArray function like QCborArray::begin () 或 QCborArray::end (). Iteration is only possible after that.

Most QCborArray functions accept an integer index rather than an iterator. For that reason, iterators are rarely useful in connection with QCborArray . One place where STL-style iterators do make sense is as arguments to 一般算法 .

Multiple iterators can be used on the same array. However, be aware that any non-const function call performed on the QCborArray will render all existing iterators undefined.

另請參閱 QCborArray::Iterator .

成員類型文檔編製

typedef ConstIterator:: iterator_category

同義詞 std::random_access_iterator_tag indicating this iterator is a random access iterator.

成員函數文檔編製

bool ConstIterator:: operator>= (const ConstIterator & other ) const

bool ConstIterator:: operator>= (const Iterator & other ) const

返迴 true if the entry in the array pointed to by this iterator occurs after or is the same entry as is pointed to by the other iterator.

bool ConstIterator:: operator> (const ConstIterator & other ) const

bool ConstIterator:: operator> (const Iterator & other ) const

返迴 true if the entry in the array pointed to by this iterator occurs after the entry pointed to by the other iterator.

bool ConstIterator:: operator<= (const ConstIterator & other ) const

bool ConstIterator:: operator<= (const Iterator & other ) const

返迴 true if the entry in the array pointed to by this iterator occurs before or is the same entry as is pointed to by the other iterator.

bool ConstIterator:: operator< (const ConstIterator & other ) const

bool ConstIterator:: operator< (const Iterator & other ) const

返迴 true if the entry in the array pointed to by this iterator occurs before the entry pointed to by the other iterator.

bool ConstIterator:: operator!= (const ConstIterator & o ) const

bool ConstIterator:: operator!= (const Iterator & o ) const

返迴 true if o points to a different entry in the array than this iterator; otherwise returns false .

另請參閱 operator== ().

bool ConstIterator:: operator== (const ConstIterator & other ) const

bool ConstIterator:: operator== (const Iterator & other ) const

返迴 true if other points to the same entry in the array as this iterator; otherwise returns false .

另請參閱 operator!= ().

ConstIterator:: ConstIterator (const ConstIterator & other )

構造副本為 other .

ConstIterator:: ConstIterator ()

Constructs an uninitialized iterator.

Functions like operator*() and operator++() should not be called on an uninitialized iterator. Use operator=() to assign a value to it before using it.

另請參閱 QCborArray::constBegin () 和 QCborArray::constEnd ().

ConstIterator &ConstIterator:: operator= (const ConstIterator & other )

Makes this iterator a copy of other and returns a reference to this iterator.

const QCborValueRef ConstIterator:: operator* () const

返迴當前項。

ConstIterator ConstIterator:: operator+ ( qsizetype j ) const

Returns an iterator to the item at a position j steps forward from this iterator. If j is negative, the iterator goes backward.

另請參閱 operator- () 和 operator+= ().

ConstIterator &ConstIterator:: operator++ ()

The prefix ++ operator, ++it , advances the iterator to the next item in the array and returns this iterator.

Calling this function on QCborArray::end () leads to undefined results.

另請參閱 operator-- ().

ConstIterator ConstIterator:: operator++ ( int )

這是重載函數。

The postfix ++ operator, it++ , advances the iterator to the next item in the array and returns an iterator to the previously current item.

ConstIterator &ConstIterator:: operator+= ( qsizetype j )

推進迭代器 j positions. If j is negative, the iterator goes backward. Returns a reference to this iterator.

另請參閱 operator-= () 和 operator+ ().

ConstIterator ConstIterator:: operator- ( qsizetype j ) const

Returns an iterator to the item at a position j steps backward from this iterator. If j is negative, the iterator goes forward.

另請參閱 operator+ () 和 operator-= ().

qsizetype ConstIterator:: operator- ( ConstIterator other ) const

Returns the offset of this iterator relative to other .

ConstIterator &ConstIterator:: operator-- ()

The prefix -- operator, --it , makes the preceding item current and returns this iterator.

Calling this function on QCborArray::begin () leads to undefined results.

另請參閱 operator++ ().

ConstIterator ConstIterator:: operator-- ( int )

這是重載函數。

The postfix -- operator, it-- , makes the preceding item current and returns an iterator to the previously current item.

ConstIterator &ConstIterator:: operator-= ( qsizetype j )

Makes the iterator go back by j positions. If j is negative, the iterator goes forward. Returns a reference to this iterator.

另請參閱 operator+= () 和 operator- ().

const QCborValueRef *ConstIterator:: operator-> () const

Returns a pointer to the current item.

const QCborValueRef ConstIterator:: operator[] ( qsizetype j )

Returns the item at a position j steps forward from the item pointed to by this iterator.

This function is provided to make QCborArray iterators behave like C++ pointers.

另請參閱 operator+ ().