# std::num_get< _CharT, _InIter > Class Template Reference

Inheritance diagram for std::num_get< _CharT, _InIter >:

List of all members.

## Detailed Description

### template<typename _CharT, typename _InIter>
class std::num_get< _CharT, _InIter >

This facet encapsulates the code to parse and return a number from a string. It is used by the istream numeric extraction operators.

The num_get template uses protected virtual functions to provide the actual results. The public accessors forward the call to the virtual functions. These virtual functions are hooks for developers to implement the behavior they require from the num_get facet.

Definition at line 1932 of file locale_facets.h.

## Public Types

- typedef _CharT char_type
- typedef _InIter iter_type

## Public Member Functions

- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, void *&__v) const
- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, bool &__v) const
- num_get (size_t __refs=0)

- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, long double &__v) const
- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, double &__v) const
- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, float &__v) const

- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, unsigned long long &__v) const
- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, long long &__v) const
- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, unsigned long &__v) const
- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, unsigned int &__v) const
- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, unsigned short &__v) const
- iter_type get (iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, long &__v) const

## Static Public Attributes

- static locale::id id

## Protected Member Functions

- iter_type _M_extract_float (iter_type, iter_type, ios_base &, ios_base::iostate &, string &__xtrc) const
- template<typename _ValueT> iter_type _M_extract_int (iter_type, iter_type, ios_base &, ios_base::iostate &, _ValueT &__v) const
- template<typename _CharT2> __gnu_cxx::__enable_if<!__is_char<
  _CharT2 >::__value, int
  >::__type _M_find (const _CharT2 *__zero, size_t __len, _CharT2 __c) const
- template<typename _CharT2> __gnu_cxx::__enable_if< __is_char<
  _CharT2 >::__value, int
  >::__type _M_find (const _CharT2 *, size_t __len, _CharT2 __c) const
- virtual ~num_get ()

- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, void *&) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, long double &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, double &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, float &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, unsigned long long &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, long long &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, unsigned long &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, unsigned int &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &__err, unsigned short &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &, long &) const
- virtual iter_type do_get (iter_type, iter_type, ios_base &, ios_base::iostate &, bool &) const

## Static Protected Member Functions

- static __c_locale _S_clone_c_locale (__c_locale &__cloc)
- static void _S_create_c_locale (__c_locale &__cloc, const char *__s, __c_locale __old=0)
- static void _S_destroy_c_locale (__c_locale &__cloc)
- static __c_locale _S_get_c_locale ()
- static const char * _S_get_c_name ()

## Friends

- class locale::_Impl

## Member Typedef Documentation

template<typename _CharT, typename _InIter>

typedef _CharT std::num_get< _CharT, _InIter >::char_type

Public typedefs.

Definition at line 1938 of file locale_facets.h.

template<typename _CharT, typename _InIter>

typedef _InIter std::num_get< _CharT, _InIter >::iter_type

Public typedefs.

Definition at line 1939 of file locale_facets.h.

## Constructor & Destructor Documentation

template<typename _CharT, typename _InIter>

std::num_get< _CharT, _InIter >::num_get | ( | size_t | __refs = `0` | ) | `[inline, explicit]`

Constructor performs initialization.

This is the constructor provided by the standard.

Parameters:

  | refs | Passed to the base facet class.

Definition at line 1953 of file locale_facets.h.

template<typename _CharT, typename _InIter>

virtual std::num_get< _CharT, _InIter >::~num_get | ( |  | ) | `[inline, protected, virtual]`

Destructor.

Definition at line 2122 of file locale_facets.h.

## Member Function Documentation

template<typename _CharT, typename _InIter>

_InIter std::num_get< _CharT, _InIter >::do_get | ( | iter_type | ,
|  | iter_type | ,
|  | ios_base & | ,
|  | ios_base::iostate & | ,
|  | bool & |  |
| ) |  |  | const`[protected, virtual]`

Numeric parsing.

Parses the input stream into the variable v. This function is a hook for derived classes to change the value returned.

See also:
  get() for more details.

Parameters:

  | in | Start of input stream.
  | end | End of input stream.
  | io | Source of locale and flags.
  | err | Error flags to set.
  | v | Value to format and insert.

Returns:
  Iterator after reading.

Definition at line 717 of file locale_facets.tcc.

References std::num_get< _CharT, _InIter >::_M_extract_int(), std::ios_base::_M_getloc(), std::ios_base::boolalpha, std::ios_base::eofbit, std::ios_base::failbit, and std::ios_base::flags().

Referenced by std::num_get< _CharT, _InIter >::get().

template<typename _CharT, typename _InIter>

iter_type std::num_get< _CharT, _InIter >::get | ( | iter_type | __in,
|  | iter_type | __end,
|  | ios_base & | __io,
|  | ios_base::iostate & | __err,
|  | void *& | __v |
| ) |  |  | const`[inline]`

Numeric parsing.

Parses the input stream into the pointer variable v. It does so by calling num_get::do_get().

The input characters are parsed like the scanf p specifier.

Digit grouping is intrepreted according to numpunct::grouping() and numpunct::thousands_sep(). If the pattern of digit groups isn't consistent, sets err to ios_base::failbit.

Note that the digit grouping effect for pointers is a bit ambiguous in the standard and shouldn't be relied on. See DR 344.

If parsing the string yields a valid value for v, v is set. Otherwise, sets err to ios_base::failbit and leaves v unaltered. Sets err to ios_base::eofbit if the stream is emptied.

Parameters:

  | in | Start of input stream.
  | end | End of input stream.
  | io | Source of locale and flags.
  | err | Error flags to set.
  | v | Value to format and insert.

Returns:
  Iterator after reading.

Definition at line 2116 of file locale_facets.h.

References std::num_get< _CharT, _InIter >::do_get().

template<typename _CharT, typename _InIter>

iter_type std::num_get< _CharT, _InIter >::get | ( | iter_type | __in,
|  | iter_type | __end,
|  | ios_base & | __io,
|  | ios_base::iostate & | __err,
|  | float & | __v |
| ) |  |  | const`[inline]`

Numeric parsing.

Parses the input stream into the integral variable v. It does so by calling num_get::do_get().

The input characters are parsed like the scanf g specifier. The matching type length modifier is also used.

The decimal point character used is numpunct::decimal_point(). Digit grouping is intrepreted according to numpunct::grouping() and numpunct::thousands_sep(). If the pattern of digit groups isn't consistent, sets err to ios_base::failbit.

If parsing the string yields a valid value for v, v is set. Otherwise, sets err to ios_base::failbit and leaves v unaltered. Sets err to ios_base::eofbit if the stream is emptied.

Parameters:

  | in | Start of input stream.
  | end | End of input stream.
  | io | Source of locale and flags.
  | err | Error flags to set.
  | v | Value to format and insert.

Returns:
  Iterator after reading.

Definition at line 2074 of file locale_facets.h.

References std::num_get< _CharT, _InIter >::do_get().

template<typename _CharT, typename _InIter>

iter_type std::num_get< _CharT, _InIter >::get | ( | iter_type | __in,
|  | iter_type | __end,
|  | ios_base & | __io,
|  | ios_base::iostate & | __err,
|  | long & | __v |
| ) |  |  | const`[inline]`

Numeric parsing.

Parses the input stream into the integral variable v. It does so by calling num_get::do_get().

Parsing is affected by the flag settings in io.

The basic parse is affected by the value of io.flags() & ios_base::basefield. If equal to ios_base::oct, parses like the scanf o specifier. Else if equal to ios_base::hex, parses like X specifier. Else if basefield equal to 0, parses like the i specifier. Otherwise, parses like d for signed and u for unsigned types. The matching type length modifier is also used.

Digit grouping is intrepreted according to numpunct::grouping() and numpunct::thousands_sep(). If the pattern of digit groups isn't consistent, sets err to ios_base::failbit.

If parsing the string yields a valid value for v, v is set. Otherwise, sets err to ios_base::failbit and leaves v unaltered. Sets err to ios_base::eofbit if the stream is emptied.

Parameters:

  | in | Start of input stream.
  | end | End of input stream.
  | io | Source of locale and flags.
  | err | Error flags to set.
  | v | Value to format and insert.

Returns:
  Iterator after reading.

Definition at line 2015 of file locale_facets.h.

References std::num_get< _CharT, _InIter >::do_get().

template<typename _CharT, typename _InIter>

iter_type std::num_get< _CharT, _InIter >::get | ( | iter_type | __in,
|  | iter_type | __end,
|  | ios_base & | __io,
|  | ios_base::iostate & | __err,
|  | bool & | __v |
| ) |  |  | const`[inline]`

Numeric parsing.

Parses the input stream into the bool v. It does so by calling num_get::do_get().

If ios_base::boolalpha is set, attempts to read ctype<CharT>::truename() or ctype<CharT>::falsename(). Sets v to true or false if successful. Sets err to ios_base::failbit if reading the string fails. Sets err to ios_base::eofbit if the stream is emptied.

If ios_base::boolalpha is not set, proceeds as with reading a long, except if the value is 1, sets v to true, if the value is 0, sets v to false, and otherwise set err to ios_base::failbit.

Parameters:

  | in | Start of input stream.
  | end | End of input stream.
  | io | Source of locale and flags.
  | err | Error flags to set.
  | v | Value to format and insert.

Returns:
  Iterator after reading.

Definition at line 1979 of file locale_facets.h.

References std::num_get< _CharT, _InIter >::do_get().

Referenced by std::basic_istream< _CharT, _Traits >::_M_extract().

## Member Data Documentation

template<typename _CharT, typename _InIter>

locale::id std::num_get< _CharT, _InIter >::id`[static]`

Numpunct facet id.

Definition at line 1943 of file locale_facets.h.

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

- locale_facets.h
- locale_facets.tcc