const_iterator 类

class QDirListing ::const_iterator

This class was introduced in Qt 6.8.

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const_iterator is part of 输入/输出和网络 .

公共类型

	pointer
	reference

公共函数

QDirListing::const_iterator::reference	operator* () const
QDirListing::const_iterator &	operator++ ()
void	operator++ (int)
QDirListing::const_iterator::pointer	operator-> () const

详细描述

The iterator type returned by QDirListing::cbegin ().

This is a forward-only, single-pass iterator (you cannot iterate directory entries in reverse order)
Can't be copied, only std::move() d.
The return value of post-increment on objects that model std::input_iterator is partially-formed (a copy of an iterator that has since been advanced), the only valid operations on such an object are destruction and assignment of a new iterator. Therefore the post-increment operator advances the iterator and returns void .
Doesn't allow random access
Can be used in ranged-for loops; or with C++20 std::ranges algorithms that don't require random access iterators
Dereferencing a valid iterator returns a const DirEntry &
(c) end () 返回 QDirListing::sentinel that signals the end of the iteration. Dereferencing an iterator that compares equal to end () is undefined behavior

注意： The "classical" STL algorithms don't support iterator/sentinel, so you need to use C++20 std::ranges algorithms for QDirListing , or else a 3rd-party library that provides range-based algorithms in C++17.

另请参阅 QDirListing , QDirListing::sentinel ，和 QDirListing::DirEntry .

成员类型文档编制

`[alias]` const_iterator:: pointer

A typedef for const QDirListing::DirEntry * .

`[alias]` const_iterator:: reference

A typedef for const QDirListing::DirEntry & .

成员函数文档编制

QDirListing::const_iterator::reference const_iterator:: operator* () const

返回 const QDirListing::DirEntry & of the directory entry this iterator points to.

QDirListing::const_iterator &const_iterator:: operator++ ()

Pre-increment operator. Advances the iterator and returns a reference to it.

void const_iterator:: operator++ ( int )

Post-increment operator.

QDirListing::const_iterator models C++20 std::input_iterator , that is, it is a move-only, forward-only, single-pass iterator, that doesn't allow random access.

The return value of post-increment on objects that model std::input_iterator is partially-formed (a copy of an iterator that has since been advanced), the only valid operations on such an object are destruction and assignment of a new iterator. Therefore the post-increment operator advances the iterator and returns void .

QDirListing::const_iterator::pointer const_iterator:: operator-> () const

返回 const QDirListing::DirEntry * to the directory entry this iterator points to.