pqxx::result::result::const_iterator Class Reference

Iterator for rows (tuples) in a query result set. More...

#include <result.hxx>

Inheritance diagram for pqxx::result::result::const_iterator:

Inheritance graph
[legend]

List of all members.

Public Types

typedef const tuplepointer
typedef tuple reference
typedef result::size_type size_type
typedef result::difference_type difference_type

Public Member Functions

 const_iterator () throw ()
 const_iterator (const tuple &t) throw ()
Dereferencing operators
pointer operator-> () const
reference operator* () const
Manipulations
const_iterator operator++ (int)
const_iteratoroperator++ ()
const_iterator operator-- (int)
const_iteratoroperator-- ()
const_iteratoroperator+= (difference_type i)
const_iteratoroperator-= (difference_type i)
Comparisons
bool operator== (const const_iterator &i) const
bool operator!= (const const_iterator &i) const
bool operator< (const const_iterator &i) const
bool operator<= (const const_iterator &i) const
bool operator> (const const_iterator &i) const
bool operator>= (const const_iterator &i) const

Friends

class pqxx::result

Arithmetic operators

const_iterator operator+ (difference_type, const_iterator)
const_iterator operator+ (difference_type) const
const_iterator operator- (difference_type) const
difference_type operator- (const_iterator) const


Detailed Description

Iterator for rows (tuples) in a query result set.

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 tuples without changing them.


Member Typedef Documentation

typedef result::difference_type pqxx::result::result::const_iterator::difference_type

Reimplemented from pqxx::result::result::tuple.

typedef const tuple* pqxx::result::result::const_iterator::pointer

Reimplemented from pqxx::result::result::tuple.

typedef tuple pqxx::result::result::const_iterator::reference

Reimplemented from pqxx::result::result::tuple.

typedef result::size_type pqxx::result::result::const_iterator::size_type

Reimplemented from pqxx::result::result::tuple.


Constructor & Destructor Documentation

pqxx::result::result::const_iterator::const_iterator (  )  throw ()

pqxx::result::result::const_iterator::const_iterator ( const tuple t  )  throw ()


Member Function Documentation

bool pqxx::result::result::const_iterator::operator!= ( const const_iterator i  )  const

reference pqxx::result::result::const_iterator::operator* (  )  const

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

const_iterator& pqxx::result::result::const_iterator::operator++ (  ) 

pqxx::result::const_iterator pqxx::result::result::const_iterator::operator++ ( int   ) 

const_iterator& pqxx::result::result::const_iterator::operator+= ( difference_type  i  ) 

result::const_iterator::difference_type pqxx::result::result::const_iterator::operator- ( const_iterator  i  )  const

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

const_iterator& pqxx::result::result::const_iterator::operator-- (  ) 

pqxx::result::const_iterator pqxx::result::result::const_iterator::operator-- ( int   ) 

const_iterator& pqxx::result::result::const_iterator::operator-= ( difference_type  i  ) 

pointer pqxx::result::result::const_iterator::operator-> (  )  const

The iterator "points to" its own tuple, which is also itself. This allows a result to be addressed as a two-dimensional container without going through the intermediate step of dereferencing the iterator. I hope this works out to be similar to C pointer/array semantics in useful cases.

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.

bool pqxx::result::result::const_iterator::operator< ( const const_iterator i  )  const

bool pqxx::result::result::const_iterator::operator<= ( const const_iterator i  )  const

bool pqxx::result::result::const_iterator::operator== ( const const_iterator i  )  const

bool pqxx::result::result::const_iterator::operator> ( const const_iterator i  )  const

bool pqxx::result::result::const_iterator::operator>= ( const const_iterator i  )  const


Friends And Related Function Documentation

const_iterator operator+ ( difference_type  o,
result::const_iterator  i 
) [friend]

friend class pqxx::result [friend]


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

Generated on Sat Aug 15 00:16:54 2009 for libpqxx by  doxygen 1.5.8