The QFuture::const_iterator 类提供 STL 样式 const 迭代器为 QFuture . 更多...
该类在 Qt 4.4 引入。
注意: 此类的所有函数 可重入 .
typedef | difference_type |
typedef | iterator_category |
typedef | pointer |
typedef | reference |
typedef | value_type |
const_iterator (const const_iterator & other ) | |
const_iterator () | |
const_iterator & | operator= (const const_iterator & other ) |
bool | operator!= (const const_iterator & other ) const |
const T & | operator* () const |
const_iterator | operator+ (int j ) const |
const_iterator & | operator++ () |
const_iterator | operator++ ( int ) |
const_iterator & | operator+= (int j ) |
const_iterator | operator- (int j ) const |
const_iterator & | operator-- () |
const_iterator | operator-- ( int ) |
const_iterator & | operator-= (int j ) |
const T * | operator-> () const |
bool | operator== (const const_iterator & other ) const |
QFuture provides both STL 样式迭代器 and Java 风格迭代器 . The STL-style iterators are more low-level and more cumbersome to use; on the other hand, they are slightly faster and, for developers who already know STL, have the advantage of familiarity.
默认 QFuture::const_iterator constructor creates an uninitialized iterator. You must initialize it using a QFuture function like QFuture::constBegin () 或 QFuture::constEnd () before you start iterating. Here's a typical loop that prints all the results available in a future:
QFuture<QString> future = ...; QFuture<QString>::const_iterator i; for (i = future.constBegin(); i != future.constEnd(); ++i) cout << *i << Qt::endl;
另请参阅 QFutureIterator and QFuture .
typedef 对于 ptrdiff_t。为兼容 STL 提供。
Typedef for std::bidirectional_iterator_tag. Provided for STL compatibility.
Typedef for const T *. Provided for STL compatibility.
Typedef for const T &. Provided for STL compatibility.
typedef 对于 T。为兼容 STL 提供。
构造副本为 other .
Constructs an uninitialized iterator.
Functions like operator*() and operator++() should not be called on an uninitialized iterartor. Use operator=() to assign a value to it before using it.
另请参阅 QFuture::constBegin () 和 QFuture::constEnd ().
赋值 other to this iterator.
返回
true
if
other
points to a different result than this iterator; otherwise returns
false
.
另请参阅 operator== ().
Returns the current result.
Returns an iterator to the results at j positions forward from this iterator. (If j is negative, the iterator goes backward.)
另请参阅 operator- () 和 operator+= ().
The prefix ++ operator (
++it
) advances the iterator to the next result in the future and returns an iterator to the new current result.
Calling this function on QFuture <T>::constEnd() leads to undefined results.
另请参阅 operator-- ().
这是重载函数。
The postfix ++ operator (
it++
) advances the iterator to the next result in the future and returns an iterator to the previously current result.
Advances the iterator by j results. (If j is negative, the iterator goes backward.)
另请参阅 operator-= () 和 operator+ ().
Returns an iterator to the result at j positions backward from this iterator. (If j is negative, the iterator goes forward.)
另请参阅 operator+ () 和 operator-= ().
The prefix -- operator (
--it
) makes the preceding result current and returns an iterator to the new current result.
Calling this function on QFuture <T>::constBegin() leads to undefined results.
另请参阅 operator++ ().
这是重载函数。
The postfix -- operator (
it--
) makes the preceding result current and returns an iterator to the previously current result.
Makes the iterator go back by j results. (If j is negative, the iterator goes forward.)
另请参阅 operator+= () 和 operator- ().
Returns a pointer to the current result.
返回
true
if
other
points to the same result as this iterator; otherwise returns
false
.
另请参阅 operator!= ().