Scroll to navigation

std::codecvt(3) Library Functions Manual std::codecvt(3)

NAME

std::codecvt -

class codecvt [22.2.1.5]. NB: Generic, mostly useless implementation.

SYNOPSIS

Inherits std::__codecvt_abstract_base< _InternT, _ExternT, _StateT >.

Inherited by std::codecvt_byname< _InternT, _ExternT, _StateT >.

Public Types


typedef _ExternT extern_type
typedef _InternT intern_type
typedef codecvt_base::result result
typedef _StateT state_type

Public Member Functions


bool always_noconv () const throw ()
codecvt (__c_locale __cloc, size_t __refs=0)
codecvt (size_t __refs=0)
int encoding () const throw ()
result in (state_type &__state, const extern_type *__from, const extern_type *__from_end, const extern_type *&__from_next, intern_type *__to, intern_type *__to_end, intern_type *&__to_next) const
int length (state_type &__state, const extern_type *__from, const extern_type *__end, size_t __max) const
int max_length () const throw ()
result out (state_type &__state, const intern_type *__from, const intern_type *__from_end, const intern_type *&__from_next, extern_type *__to, extern_type *__to_end, extern_type *&__to_next) const
result unshift (state_type &__state, extern_type *__to, extern_type *__to_end, extern_type *&__to_next) const

Static Public Attributes


static locale::id id

Protected Member Functions


virtual bool do_always_noconv () const throw ()
virtual int do_encoding () const throw ()
virtual result do_in (state_type &__state, const extern_type *__from, const extern_type *__from_end, const extern_type *&__from_next, intern_type *__to, intern_type *__to_end, intern_type *&__to_next) const
virtual int do_length (state_type &, const extern_type *__from, const extern_type *__end, size_t __max) const
virtual int do_max_length () const throw ()
virtual result do_out (state_type &__state, const intern_type *__from, const intern_type *__from_end, const intern_type *&__from_next, extern_type *__to, extern_type *__to_end, extern_type *&__to_next) const
virtual result do_unshift (state_type &__state, extern_type *__to, extern_type *__to_end, extern_type *&__to_next) 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 ()

Protected Attributes


__c_locale _M_c_locale_codecvt

Friends


class locale::_Impl

Detailed Description

template<typename _InternT, typename _ExternT, typename _StateT> class std::codecvt< _InternT, _ExternT, _StateT >

class codecvt [22.2.1.5]. NB: Generic, mostly useless implementation.

Definition at line 268 of file codecvt.h.

Member Function Documentation

template<typename _InternT , typename _ExternT , typename _StateT > virtual result std::codecvt< _InternT, _ExternT, _StateT >::do_out (state_type & __state, const intern_type * __from, const intern_type * __from_end, const intern_type *& __from_next, extern_type * __to, extern_type * __to_end, extern_type *& __to_next) const [protected, virtual]

Convert from internal to external character set. Converts input string of intern_type to output string of extern_type. This function is a hook for derived classes to change the value returned.

See also:

out for more information.

Implements std::__codecvt_abstract_base< _InternT, _ExternT, _StateT >.

template<typename _InternT, typename _ExternT, typename _StateT> result std::__codecvt_abstract_base< _InternT, _ExternT, _StateT >::in (state_type & __state, const extern_type * __from, const extern_type * __from_end, const extern_type *& __from_next, intern_type * __to, intern_type * __to_end, intern_type *& __to_next) const [inline, inherited]

Convert from external to internal character set. Converts input string of extern_type to output string of intern_type. This is analogous to mbsrtowcs. It does this by calling codecvt::do_in.

The source and destination character sets are determined by the facet's locale, internal and external types.

The characters in [from,from_end) are converted and written to [to,to_end). from_next and to_next are set to point to the character following the last successfully converted character, respectively. If the result needed no conversion, from_next and to_next are not affected.

The state argument should be initialized if the input is at the beginning and carried from a previous call if continuing conversion. There are no guarantees about how state is used.

The result returned is a member of codecvt_base::result. If all the input is converted, returns codecvt_base::ok. If no conversion is necessary, returns codecvt_base::noconv. If the input ends early or there is insufficient space in the output, returns codecvt_base::partial. Otherwise the conversion failed and codecvt_base::error is returned.

Parameters:

state Persistent conversion state data.
from Start of input.
from_end End of input.
from_next Returns start of unconverted data.
to Start of output buffer.
to_end End of output buffer.
to_next Returns start of unused output area.

Returns:

codecvt_base::result.

Definition at line 195 of file codecvt.h.

Referenced by std::basic_filebuf< _CharT, _Traits >::underflow().

template<typename _InternT, typename _ExternT, typename _StateT> result std::__codecvt_abstract_base< _InternT, _ExternT, _StateT >::out (state_type & __state, const intern_type * __from, const intern_type * __from_end, const intern_type *& __from_next, extern_type * __to, extern_type * __to_end, extern_type *& __to_next) const [inline, inherited]

Convert from internal to external character set. Converts input string of intern_type to output string of extern_type. This is analogous to wcsrtombs. It does this by calling codecvt::do_out.

The source and destination character sets are determined by the facet's locale, internal and external types.

The characters in [from,from_end) are converted and written to [to,to_end). from_next and to_next are set to point to the character following the last successfully converted character, respectively. If the result needed no conversion, from_next and to_next are not affected.

The state argument should be initialized if the input is at the beginning and carried from a previous call if continuing conversion. There are no guarantees about how state is used.

The result returned is a member of codecvt_base::result. If all the input is converted, returns codecvt_base::ok. If no conversion is necessary, returns codecvt_base::noconv. If the input ends early or there is insufficient space in the output, returns codecvt_base::partial. Otherwise the conversion failed and codecvt_base::error is returned.

Parameters:

state Persistent conversion state data.
from Start of input.
from_end End of input.
from_next Returns start of unconverted data.
to Start of output buffer.
to_end End of output buffer.
to_next Returns start of unused output area.

Returns:

codecvt_base::result.

Definition at line 115 of file codecvt.h.

template<typename _InternT, typename _ExternT, typename _StateT> result std::__codecvt_abstract_base< _InternT, _ExternT, _StateT >::unshift (state_type & __state, extern_type * __to, extern_type * __to_end, extern_type *& __to_next) const [inline, inherited]

Reset conversion state. Writes characters to output that would restore state to initial conditions. The idea is that if a partial conversion occurs, then the converting the characters written by this function would leave the state in initial conditions, rather than partial conversion state. It does this by calling codecvt::do_unshift().

For example, if 4 external characters always converted to 1 internal character, and input to in() had 6 external characters with state saved, this function would write two characters to the output and set the state to initialized conditions.

The source and destination character sets are determined by the facet's locale, internal and external types.

The result returned is a member of codecvt_base::result. If the state could be reset and data written, returns codecvt_base::ok. If no conversion is necessary, returns codecvt_base::noconv. If the output has insufficient space, returns codecvt_base::partial. Otherwise the reset failed and codecvt_base::error is returned.

Parameters:

state Persistent conversion state data.
to Start of output buffer.
to_end End of output buffer.
to_next Returns start of unused output area.

Returns:

codecvt_base::result.

Definition at line 154 of file codecvt.h.

Author

Generated automatically by Doxygen for libstdc++ from the source code.

19 Jun 2018 libstdc++