Contents

• Public Types
• Public Functions
• Detailed Description

Detailed Description

TheQFuture::const_iterator class provides an STL-style const iterator forQFuture.

QFuture provides bothSTL-style iterators andJava-style iterators. 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.

The defaultQFuture::const_iterator constructor creates an uninitialized iterator. You must initialize it using aQFuture function likeQFuture::constBegin() orQFuture::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<< endl;

Member Type Documentation

typedef const_iterator::difference_type

Typedef for ptrdiff_t. Provided for STL compatibility.

typedef const_iterator::iterator_category

Typedef for std::bidirectional_iterator_tag. Provided for STL compatibility.

typedef const_iterator::pointer

Typedef for const T *. Provided for STL compatibility.

typedef const_iterator::reference

Typedef for const T &. Provided for STL compatibility.

typedef const_iterator::value_type

Typedef for T. Provided for STL compatibility.

Member Function Documentation

const_iterator::const_iterator()

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.

See alsoQFuture::constBegin() andQFuture::constEnd().

const_iterator::const_iterator(constconst_iterator & other)

Constructs a copy ofother.

bool const_iterator::operator!=(constconst_iterator & other) const

Returns true ifother points to a different result than this iterator; otherwise returns false.

See alsooperator==().

constT & const_iterator::operator*() const

Returns the current result.

const_iterator const_iterator::operator+(int j) const

Returns an iterator to the results atj positions forward from this iterator. (Ifj is negative, the iterator goes backward.)

See alsooperator-() andoperator+=().

const_iterator & const_iterator::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 onQFuture::constEnd() leads to undefined results.

See alsooperator--().

const_iterator const_iterator::operator++(int)

This is an overloaded function.

The postfix ++ operator (it++) advances the iterator to the next result in the future and returns an iterator to the previously current result.

const_iterator & const_iterator::operator+=(int j)

Advances the iterator byj results. (Ifj is negative, the iterator goes backward.)

See alsooperator-=() andoperator+().

const_iterator const_iterator::operator-(int j) const

Returns an iterator to the result atj positions backward from this iterator. (Ifj is negative, the iterator goes forward.)

See alsooperator+() andoperator-=().

const_iterator & const_iterator::operator--()

The prefix -- operator (--it) makes the preceding result current and returns an iterator to the new current result.

Calling this function onQFuture::constBegin() leads to undefined results.

See alsooperator++().

const_iterator const_iterator::operator--(int)

This is an overloaded function.

The postfix -- operator (it--) makes the preceding result current and returns an iterator to the previously current result.

const_iterator & const_iterator::operator-=(int j)

Makes the iterator go back byj results. (Ifj is negative, the iterator goes forward.)

See alsooperator+=() andoperator-().

constT * const_iterator::operator->() const

Returns a pointer to the current result.

const_iterator & const_iterator::operator=(constconst_iterator & other)

Assignsother to this iterator.

bool const_iterator::operator==(constconst_iterator & other) const

Returns true ifother points to the same result as this iterator; otherwise returns false.

See alsooperator!=().