libpqxx
4.0.1
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Iterator for rows (tuples) in a result. Use as result::const_iterator. More...
#include <result.hxx>
Public Types | |
typedef const tuple * | pointer |
typedef tuple | reference |
typedef result::size_type | size_type |
typedef result::difference_type | difference_type |
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typedef tuple_size_type | size_type |
typedef tuple_difference_type | difference_type |
typedef const_tuple_iterator | const_iterator |
typedef const_iterator | iterator |
typedef field | reference |
typedef const_tuple_iterator | pointer |
typedef const_reverse_tuple_iterator | const_reverse_iterator |
typedef const_reverse_iterator | reverse_iterator |
Public Member Functions | |
const_result_iterator () throw () | |
const_result_iterator (const tuple &t) throw () | |
Dereferencing operators | |
pointer | operator-> () const |
reference | operator* () const |
Manipulations | |
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) |
Comparisons | |
bool | operator== (const const_result_iterator &i) const |
bool | operator!= (const const_result_iterator &i) const |
bool | operator< (const const_result_iterator &i) const |
bool | operator<= (const const_result_iterator &i) const |
bool | operator> (const const_result_iterator &i) const |
bool | operator>= (const const_result_iterator &i) const |
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tuple (const result *r, size_t i) throw () | |
~tuple () throw () | |
const_iterator | begin () const throw () |
const_iterator | end () const throw () |
size_type | size () const throw () |
void | swap (tuple &) throw () |
size_t | rownumber () const throw () |
size_t | num () const |
tuple | slice (size_type Begin, size_type End) const |
bool PQXX_PURE | empty () const throw () |
bool PQXX_PURE | operator== (const tuple &) const throw () |
bool | operator!= (const tuple &rhs) const throw () |
reference | front () const throw () |
reference | back () const throw () |
const_reverse_tuple_iterator | rbegin () const |
const_reverse_tuple_iterator | rend () const |
reference | operator[] (size_type) const throw () |
reference | operator[] (int) const throw () |
reference | operator[] (const char[]) const |
reference | operator[] (const std::string &) const |
reference | at (size_type) const throw (pqxx::range_error) |
reference | at (int) const throw (pqxx::range_error) |
reference | at (const char[]) const |
reference | at (const std::string &) const |
size_type | column_number (const std::string &ColName) const |
Number of given column (throws exception if it doesn't exist) | |
size_type | column_number (const char[]) const |
Number of given column (throws exception if it doesn't exist) | |
oid | column_type (size_type) const |
Type of given column. | |
oid | column_type (int ColNum) const |
Type of given column. | |
oid | column_type (const std::string &ColName) const |
Type of given column. | |
oid | column_type (const char ColName[]) const |
Type of given column. | |
oid | column_table (size_type ColNum) const |
What table did this column come from? | |
oid | column_table (int ColNum) const |
What table did this column come from? | |
oid | column_table (const std::string &ColName) const |
What table did this column come from? | |
size_type | table_column (size_type) const |
What column number in its table did this result column come from? | |
size_type | table_column (int ColNum) const |
What column number in its table did this result column come from? | |
size_type | table_column (const std::string &ColName) const |
What column number in its table did this result column come from? |
Friends | |
class | pqxx::result |
Arithmetic operators | |
const_result_iterator | operator+ (difference_type, const_result_iterator) |
const_result_iterator | operator+ (difference_type) const |
const_result_iterator | operator- (difference_type) const |
difference_type | operator- (const_result_iterator) const |
Additional Inherited Members | |
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const result * | m_Home |
size_t | m_Index |
size_type | m_Begin |
size_type | m_End |
Iterator for rows (tuples) 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 tuples without changing them.
typedef const tuple* pqxx::const_result_iterator::pointer |
pqxx::const_result_iterator::const_result_iterator | ( | ) | throw () |
pqxx::const_result_iterator::const_result_iterator | ( | const tuple & | t | ) | throw () |
bool pqxx::const_result_iterator::operator!= | ( | const const_result_iterator & | i | ) | const |
reference pqxx::const_result_iterator::operator* | ( | ) | const |
const_result_iterator pqxx::const_result_iterator::operator+ | ( | result::difference_type | o | ) | const |
pqxx::const_result_iterator pqxx::const_result_iterator::operator++ | ( | int | ) |
const_result_iterator& pqxx::const_result_iterator::operator++ | ( | ) |
const_result_iterator& pqxx::const_result_iterator::operator+= | ( | difference_type | i | ) |
const_result_iterator pqxx::const_result_iterator::operator- | ( | result::difference_type | o | ) | const |
result::difference_type pqxx::const_result_iterator::operator- | ( | const_result_iterator | i | ) | const |
References pqxx::tuple::num().
pqxx::const_result_iterator pqxx::const_result_iterator::operator-- | ( | int | ) |
const_result_iterator& pqxx::const_result_iterator::operator-- | ( | ) |
const_result_iterator& pqxx::const_result_iterator::operator-= | ( | difference_type | i | ) |
pointer pqxx::const_result_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::const_result_iterator::operator< | ( | const const_result_iterator & | i | ) | const |
bool pqxx::const_result_iterator::operator<= | ( | const const_result_iterator & | i | ) | const |
bool pqxx::const_result_iterator::operator== | ( | const const_result_iterator & | i | ) | const |
bool pqxx::const_result_iterator::operator> | ( | const const_result_iterator & | i | ) | const |
bool pqxx::const_result_iterator::operator>= | ( | const const_result_iterator & | i | ) | const |
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