Iterator for rows in a result. Use as result::const_iterator. More...

#include <result_iterator.hxx>

Inheritance diagram for pqxx::const_result_iterator:

Public Types
using	iterator_category = std::random_access_iterator_tag

using	value_type = row const

using	pointer = row const *

using	reference = row

using	size_type = result_size_type

using	difference_type = result_difference_type

Public Types inherited from pqxx::row
using	size_type = row_size_type

using	difference_type = row_difference_type

using	const_iterator = const_row_iterator

using	iterator = const_iterator

using	reference = field

using	pointer = const_row_iterator

using	const_reverse_iterator = const_reverse_row_iterator

using	reverse_iterator = const_reverse_iterator

Public Member Functions
	const_result_iterator () noexcept=default
	Create an iterator, but in an unusable state. More...

	const_result_iterator (const_result_iterator const &) noexcept=default
	Copy an iterator. More...

	const_result_iterator (const_result_iterator &&) noexcept=default
	Move an iterator. More...

	const_result_iterator (row const &t) noexcept
	Begin iterating a `row`. More...

Dereferencing operators
An iterator "points to" its own row, which is also itself. This makes it easy to address a `result` as a two-dimensional container, without going through the intermediate step of dereferencing the iterator. It makes the interface similar to C pointer/array semantics. IIRC Alex Stepanov, the inventor of the STL, once remarked that having this as standard behaviour for pointers would be useful in some algorithms. So even if this makes me look foolish, I would seem to be in distinguished company.
pointer	operator-> () const
	Dereference the iterator. More...

reference	operator* () const
	Dereference the iterator. More...

Manipulations
const_result_iterator &	operator= (const_result_iterator const &rhs)

const_result_iterator &	operator= (const_result_iterator &&rhs)

const_result_iterator	operator++ (int)

const_result_iterator &	operator++ ()

const_result_iterator	operator-- (int)

const_result_iterator &	operator-- ()

const_result_iterator &	operator+= (difference_type i)

const_result_iterator &	operator-= (difference_type i)

void	swap (const_result_iterator &other) noexcept
	Interchange two iterators in an exception-safe manner. More...

Comparisons
bool	operator== (const_result_iterator const &i) const

bool	operator!= (const_result_iterator const &i) const

bool	operator< (const_result_iterator const &i) const

bool	operator<= (const_result_iterator const &i) const

bool	operator> (const_result_iterator const &i) const

bool	operator>= (const_result_iterator const &i) const

Public Member Functions inherited from pqxx::row
	row ()=default

	row (row &&)=default

	row (row const &)=default

row &	operator= (row const &)=default

row &	operator= (row &&)=default

const_iterator	begin () const noexcept

const_iterator	cbegin () const noexcept

const_iterator	end () const noexcept

const_iterator	cend () const noexcept

result::size_type	num () const

row	slice (size_type sbegin, size_type send) const

PQXX_PURE bool	empty () const noexcept

template<typename Tuple >
void	to (Tuple &t) const
	Extract entire row's values into a tuple. More...

template<typename... TYPE>
std::tuple< TYPE... >	as () const

PQXX_PURE bool	operator== (row const &) const noexcept

bool	operator!= (row const &rhs) const noexcept

size_type	column_number (zview col_name) const
	Number of given column (throws exception if it doesn't exist). More...

oid	column_type (size_type) const
	Return a column's type. More...

oid	column_type (zview col_name) const
	Return a column's type. More...

oid	column_table (size_type col_num) const
	What table did this column come from? More...

oid	column_table (zview col_name) const
	What table did this column come from? More...

size_type	table_column (size_type) const
	What column number in its table did this result column come from? More...

size_type	table_column (zview col_name) const
	What column number in its table did this result column come from? More...

reference	front () const noexcept

reference	back () const noexcept

const_reverse_row_iterator	rbegin () const

const_reverse_row_iterator	crbegin () const

const_reverse_row_iterator	rend () const

const_reverse_row_iterator	crend () const

reference	operator[] (size_type) const noexcept

reference	operator[] (zview col_name) const

reference	at (size_type) const

reference	at (zview col_name) const

size_type	size () const noexcept

Swap not rows void	swap (row &) noexcept

result::size_type	rownumber () const noexcept
	Row number, assuming this is a real row and not end()/rend(). More...

Friends
class	pqxx::result

Arithmetic operators
const_result_iterator	operator+ (difference_type, const_result_iterator const &)

const_result_iterator	operator+ (difference_type) const

const_result_iterator	operator- (difference_type) const

difference_type	operator- (const_result_iterator const &) const

Additional Inherited Members
Public Attributes inherited from pqxx::row
Swap	iterators

Protected Member Functions inherited from pqxx::row
	row (result const &r, result_size_type i) noexcept

void	check_size (size_type expected) const
	Throw `usage_error` if row size is not `expected`. More...

template<typename Tuple >
void	convert (Tuple &t) const
	Convert entire row to tuple fields, without checking row size. More...

Protected Attributes inherited from pqxx::row
result	m_result
	Result set of which this is one row. More...

result::size_type	m_index = 0
	Row number. More...

size_type	m_begin = 0
	First column in slice. This row ignores lower-numbered columns. More...

size_type	m_end = 0
	End column in slice. This row only sees lower-numbered columns. More...

Detailed Description

Iterator for rows in a result. Use as result::const_iterator.

A result, once obtained, cannot be modified. Therefore there is no plain iterator type for result. However its const_iterator type can be used to inspect its rows without changing them.

Member Typedef Documentation

◆ difference_type

using pqxx::const_result_iterator::difference_type = result_difference_type

◆ iterator_category

using pqxx::const_result_iterator::iterator_category = std::random_access_iterator_tag

◆ pointer

using pqxx::const_result_iterator::pointer = row const *

◆ reference

using pqxx::const_result_iterator::reference = row

◆ size_type

using pqxx::const_result_iterator::size_type = result_size_type

◆ value_type

using pqxx::const_result_iterator::value_type = row const

Constructor & Destructor Documentation

◆ const_result_iterator() [1/4]

pqxx::const_result_iterator::const_result_iterator ( )

defaultnoexcept

Create an iterator, but in an unusable state.

◆ const_result_iterator() [2/4]

pqxx::const_result_iterator::const_result_iterator ( const_result_iterator const & )

defaultnoexcept

Copy an iterator.

◆ const_result_iterator() [3/4]

pqxx::const_result_iterator::const_result_iterator ( const_result_iterator && )

defaultnoexcept

Move an iterator.

◆ const_result_iterator() [4/4]

pqxx::const_result_iterator::const_result_iterator ( row const & t )

noexcept

Begin iterating a row.

Member Function Documentation

◆ operator!=()

bool pqxx::const_result_iterator::operator!= ( const_result_iterator const & i ) const

References pqxx::row::m_index.

◆ operator*()

reference pqxx::const_result_iterator::operator* ( ) const

Dereference the iterator.

References pqxx::row::at(), pqxx::row::back(), pqxx::row::front(), and pqxx::row::rownumber().

◆ operator+()

const_result_iterator pqxx::const_result_iterator::operator+ ( result::difference_type o ) const

◆ operator++() [1/2]

pqxx::const_result_iterator pqxx::const_result_iterator::operator++ ( int )

◆ operator++() [2/2]

const_result_iterator& pqxx::const_result_iterator::operator++ ( )

◆ operator+=()

const_result_iterator& pqxx::const_result_iterator::operator+= ( difference_type i )

◆ operator-() [1/2]

const_result_iterator pqxx::const_result_iterator::operator- ( result::difference_type o ) const

◆ operator-() [2/2]

result::difference_type pqxx::const_result_iterator::operator- ( const_result_iterator const & i ) const

References pqxx::row::num().

◆ operator--() [1/2]

pqxx::const_result_iterator pqxx::const_result_iterator::operator-- ( int )

◆ operator--() [2/2]

const_result_iterator& pqxx::const_result_iterator::operator-- ( )

◆ operator-=()

const_result_iterator& pqxx::const_result_iterator::operator-= ( difference_type i )

◆ operator->()

pointer pqxx::const_result_iterator::operator-> ( ) const

Dereference the iterator.

◆ operator<()

bool pqxx::const_result_iterator::operator< ( const_result_iterator const & i ) const

References pqxx::row::m_index.

◆ operator<=()

bool pqxx::const_result_iterator::operator<= ( const_result_iterator const & i ) const

References pqxx::row::m_index.

◆ operator=() [1/2]

const_result_iterator& pqxx::const_result_iterator::operator= ( const_result_iterator const & rhs )

References pqxx::row::operator=().

◆ operator=() [2/2]

const_result_iterator& pqxx::const_result_iterator::operator= ( const_result_iterator && rhs )

References pqxx::row::operator=().

◆ operator==()

bool pqxx::const_result_iterator::operator== ( const_result_iterator const & i ) const

References pqxx::row::m_index.

◆ operator>()

bool pqxx::const_result_iterator::operator> ( const_result_iterator const & i ) const

References pqxx::row::m_index.

◆ operator>=()

bool pqxx::const_result_iterator::operator>= ( const_result_iterator const & i ) const

References pqxx::row::m_index, and pqxx::operator+().

◆ swap()

void pqxx::const_result_iterator::swap ( const_result_iterator & other )

noexcept

Interchange two iterators in an exception-safe manner.

References pqxx::row::swap().

Referenced by pqxx::const_reverse_result_iterator::swap().

Friends And Related Function Documentation

◆ operator+

const_result_iterator operator+	(	result::difference_type	o,
		const_result_iterator const &	i
	)

friend

◆ pqxx::result

friend class pqxx::result

friend

The documentation for this class was generated from the following files:

result_iterator.hxx
result.cxx

Public Types

Public Member Functions

Friends

Arithmetic operators

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ difference_type

◆ iterator_category

◆ pointer

◆ reference

◆ size_type

◆ value_type

Constructor & Destructor Documentation

◆ const_result_iterator() [1/4]

◆ const_result_iterator() [2/4]

◆ const_result_iterator() [3/4]

◆ const_result_iterator() [4/4]

Member Function Documentation

◆ operator!=()

◆ operator*()

◆ operator+()

◆ operator++() [1/2]

◆ operator++() [2/2]

◆ operator+=()

◆ operator-() [1/2]

◆ operator-() [2/2]

◆ operator--() [1/2]

◆ operator--() [2/2]

◆ operator-=()

◆ operator->()

◆ operator<()

◆ operator<=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()

◆ operator>()

◆ operator>=()

◆ swap()

Friends And Related Function Documentation

◆ operator+

◆ pqxx::result