ConstIterator 类

class QCborMap ::ConstIterator

The QCborMap::ConstIterator 类提供 STL 样式 const 迭代器为 QCborMap . 更多...

• 所有成员列表，包括继承成员
• ConstIterator is part of 在 Qt 中支持 CBOR .

此类 强烈可比较 .

此类 强烈可比较 with Iterator .

公共类型

iterator_category

公共函数

	ConstIterator ()
	ConstIterator (const QCborMap::ConstIterator & other )
QCborValue	key () const
QCborValueConstRef	value () const
QCborMap::ConstIterator::value_type	operator* () const
QCborMap::ConstIterator	operator+ (qsizetype j ) const
QCborMap::ConstIterator &	operator++ ()
QCborMap::ConstIterator	operator++ (int)
QCborMap::ConstIterator &	operator+= (qsizetype j )
qsizetype	operator- (QCborMap::ConstIterator j ) const
QCborMap::ConstIterator	operator- (qsizetype j ) const
QCborMap::ConstIterator &	operator-- ()
QCborMap::ConstIterator	operator-- (int)
QCborMap::ConstIterator &	operator-= (qsizetype j )
const QCborValueConstRef *	operator-> () const
QCborMap::ConstIterator &	operator= (const QCborMap::ConstIterator & other )

相关非成员

bool	operator!= (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )
bool	operator< (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )
bool	operator<= (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )
bool	operator== (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )
bool	operator> (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )
bool	operator>= (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )

详细描述

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

You must initialize the iterator using a QCborMap function like QCborMap::begin (), QCborMap::end ()，或 QCborMap::find () before you can start iterating..

Multiple iterators can be used on the same object. Existing iterators will however become dangling if the object gets modified.

另请参阅 QCborMap::Iterator .

成员类型文档编制

ConstIterator:: iterator_category

同义词 std::random_access_iterator_tag indicating this iterator is a random-access iterator.

成员函数文档编制

[constexpr noexcept] ConstIterator:: ConstIterator ()

Constructs an uninitialized iterator.

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

另请参阅 QCborMap::constBegin () 和 QCborMap::constEnd ().

[constexpr noexcept] ConstIterator:: ConstIterator (const QCborMap::ConstIterator & other )

Constructs an iterator as a copy of other .

QCborValue ConstIterator:: key () const

Returns the current item's key.

另请参阅 value ().

QCborValueConstRef ConstIterator:: value () const

Returns the current item's value.

另请参阅 key () 和 operator* ().

QCborMap::ConstIterator::value_type ConstIterator:: operator* () const

Returns a pair containing the current item's key and value.

另请参阅 key () 和 value ().

QCborMap::ConstIterator ConstIterator:: operator+ ( qsizetype j ) const

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

另请参阅 operator- ().

QCborMap::ConstIterator &ConstIterator:: operator++ ()

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

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

另请参阅 operator-- ().

QCborMap::ConstIterator ConstIterator:: operator++ ( int )

这是重载函数。

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

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

Advances the iterator by j items. If j is negative, the iterator goes backward. Returns a reference to this iterator.

另请参阅 operator-= () 和 operator+ ().

qsizetype ConstIterator:: operator- ( QCborMap::ConstIterator j ) const

Returns the position of the item at iterator j relative to the item at this iterator. If the item at j is forward of this time, the returned value is negative.

另请参阅 operator+ ().

QCborMap::ConstIterator ConstIterator:: operator- ( qsizetype j ) const

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

另请参阅 operator+ ().

QCborMap::ConstIterator &ConstIterator:: operator-- ()

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

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

另请参阅 operator++ ().

QCborMap::ConstIterator ConstIterator:: operator-- ( int )

这是重载函数。

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

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

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

另请参阅 operator+= () 和 operator- ().

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

Returns a pointer to the current pair's value.

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

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

相关非成员

[noexcept] bool operator!= (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )

返回 true if lhs points to a different entry in the map than rhs iterator; otherwise returns false .

另请参阅 operator== ().

[noexcept] bool operator< (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )

返回 true if the entry in the map pointed to by lhs iterator occurs before the entry pointed to by the rhs iterator.

[noexcept] bool operator<= (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )

返回 true if the entry in the map pointed to by lhs iterator occurs before or is the same entry as is pointed to by the rhs iterator.

[noexcept] bool operator== (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )

返回 true if lhs points to the same entry in the map as rhs iterator; otherwise returns false .

另请参阅 operator!= ().

[noexcept] bool operator> (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )

返回 true if the entry in the map pointed to by lhs iterator occurs after the entry pointed to by the rhs iterator.

[noexcept] bool operator>= (const QCborMap::ConstIterator & lhs , const QCborMap::ConstIterator & rhs )

返回 true if the entry in the map pointed to by lhs iterator occurs after or is the same entry as is pointed to by the rhs iterator.

内容

1. 公共类型

2. 公共函数

3. 相关非成员

4. 详细描述