Software: Apache/2.0.54 (Fedora). PHP/5.0.4 

uname -a: Linux mina-info.me 2.6.17-1.2142_FC4smp #1 SMP Tue Jul 11 22:57:02 EDT 2006 i686 

uid=48(apache) gid=48(apache) groups=48(apache)
context=system_u:system_r:httpd_sys_script_t 

Safe-mode: OFF (not secure)

/usr/share/doc/libstdc++-devel-4.0.2/html/22_locale/   drwxr-xr-x
Free 3.77 GB of 27.03 GB (13.93%)
                            Encoder    Tools    Proc.    FTP brute    Sec.    SQL    PHP-code    Update    Feedback    Self remove    Logout    

Viewing file:     locale.html (8.77 KB)      -rw-r--r--

Notes on the locale implementation.

1. Abstract

Describes the basic locale object, including nested classes id, facet, and the reference-counted implementation object, class _Impl.

2. What the standard says

class facet 22.1.1.1.2 Class locale::facet

Facets actually implement locale functionality. For instance, a facet called numpunct is the data objects that can be used to query for the thousands separator is in the German locale.

• containing the following public data member:

  static locale::id id;

• derived from another facet:

  class gnu_codecvt: public std::ctype<user-defined-type>

Of interest in this class are the memory management options explicitly specified as an argument to facet's constructor. Each constructor of a facet class takes a std::size_t __refs argument: if __refs == 0, the facet is deleted when the locale containing it is destroyed. If __refs == 1, the facet is not destroyed, even when it is no longer referenced.

class id 22.1.1.1.3 - Class locale::id

Provides an index for looking up specific facets.

3. Interacting with "C" locales.

Some help on determining the underlying support for locales on a system. Note, this is specific to linux (and glibc-2.3.x)

• `locale -a` displays available locales.

  af_ZA
  ar_AE
  ar_AE.utf8
  ar_BH
  ar_BH.utf8
  ar_DZ
  ar_DZ.utf8
  ar_EG
  ar_EG.utf8
  ar_IN
  ar_IQ
  ar_IQ.utf8
  ar_JO
  ar_JO.utf8
  ar_KW
  ar_KW.utf8
  ar_LB
  ar_LB.utf8
  ar_LY
  ar_LY.utf8
  ar_MA
  ar_MA.utf8
  ar_OM
  ar_OM.utf8
  ar_QA
  ar_QA.utf8
  ar_SA
  ar_SA.utf8
  ar_SD
  ar_SD.utf8
  ar_SY
  ar_SY.utf8
  ar_TN
  ar_TN.utf8
  ar_YE
  ar_YE.utf8
  be_BY
  be_BY.utf8
  bg_BG
  bg_BG.utf8
  br_FR
  bs_BA
  C
  ca_ES
  ca_ES@euro
  ca_ES.utf8
  ca_ES.utf8@euro
  cs_CZ
  cs_CZ.utf8
  cy_GB
  da_DK
  da_DK.iso885915
  da_DK.utf8
  de_AT
  de_AT@euro
  de_AT.utf8
  de_AT.utf8@euro
  de_BE
  de_BE@euro
  de_BE.utf8
  de_BE.utf8@euro
  de_CH
  de_CH.utf8
  de_DE
  de_DE@euro
  de_DE.utf8
  de_DE.utf8@euro
  de_LU
  de_LU@euro
  de_LU.utf8
  de_LU.utf8@euro
  el_GR
  el_GR.utf8
  en_AU
  en_AU.utf8
  en_BW
  en_BW.utf8
  en_CA
  en_CA.utf8
  en_DK
  en_DK.utf8
  en_GB
  en_GB.iso885915
  en_GB.utf8
  en_HK
  en_HK.utf8
  en_IE
  en_IE@euro
  en_IE.utf8
  en_IE.utf8@euro
  en_IN
  en_NZ
  en_NZ.utf8
  en_PH
  en_PH.utf8
  en_SG
  en_SG.utf8
  en_US
  en_US.iso885915
  en_US.utf8
  en_ZA
  en_ZA.utf8
  en_ZW
  en_ZW.utf8
  es_AR
  es_AR.utf8
  es_BO
  es_BO.utf8
  es_CL
  es_CL.utf8
  es_CO
  es_CO.utf8
  es_CR
  es_CR.utf8
  es_DO
  es_DO.utf8
  es_EC
  es_EC.utf8
  es_ES
  es_ES@euro
  es_ES.utf8
  es_ES.utf8@euro
  es_GT
  es_GT.utf8
  es_HN
  es_HN.utf8
  es_MX
  es_MX.utf8
  es_NI
  es_NI.utf8
  es_PA
  es_PA.utf8
  es_PE
  es_PE.utf8
  es_PR
  es_PR.utf8
  es_PY
  es_PY.utf8
  es_SV
  es_SV.utf8
  es_US
  es_US.utf8
  es_UY
  es_UY.utf8
  es_VE
  es_VE.utf8
  et_EE
  et_EE.utf8
  eu_ES
  eu_ES@euro
  eu_ES.utf8
  eu_ES.utf8@euro
  fa_IR
  fi_FI
  fi_FI@euro
  fi_FI.utf8
  fi_FI.utf8@euro
  fo_FO
  fo_FO.utf8
  fr_BE
  fr_BE@euro
  fr_BE.utf8
  fr_BE.utf8@euro
  fr_CA
  fr_CA.utf8
  fr_CH
  fr_CH.utf8
  fr_FR
  fr_FR@euro
  fr_FR.utf8
  fr_FR.utf8@euro
  fr_LU
  fr_LU@euro
  fr_LU.utf8
  fr_LU.utf8@euro
  ga_IE
  ga_IE@euro
  ga_IE.utf8
  ga_IE.utf8@euro
  gl_ES
  gl_ES@euro
  gl_ES.utf8
  gl_ES.utf8@euro
  gv_GB
  gv_GB.utf8
  he_IL
  he_IL.utf8
  hi_IN
  hr_HR
  hr_HR.utf8
  hu_HU
  hu_HU.utf8
  id_ID
  id_ID.utf8
  is_IS
  is_IS.utf8
  it_CH
  it_CH.utf8
  it_IT
  it_IT@euro
  it_IT.utf8
  it_IT.utf8@euro
  iw_IL
  iw_IL.utf8
  ja_JP.eucjp
  ja_JP.utf8
  ka_GE
  kl_GL
  kl_GL.utf8
  ko_KR.euckr
  ko_KR.utf8
  kw_GB
  kw_GB.utf8
  lt_LT
  lt_LT.utf8
  lv_LV
  lv_LV.utf8
  mi_NZ
  mk_MK
  mk_MK.utf8
  mr_IN
  ms_MY
  ms_MY.utf8
  mt_MT
  mt_MT.utf8
  nl_BE
  nl_BE@euro
  nl_BE.utf8
  nl_BE.utf8@euro
  nl_NL
  nl_NL@euro
  nl_NL.utf8
  nl_NL.utf8@euro
  nn_NO
  nn_NO.utf8
  no_NO
  no_NO.utf8
  oc_FR
  pl_PL
  pl_PL.utf8
  POSIX
  pt_BR
  pt_BR.utf8
  pt_PT
  pt_PT@euro
  pt_PT.utf8
  pt_PT.utf8@euro
  ro_RO
  ro_RO.utf8
  ru_RU
  ru_RU.koi8r
  ru_RU.utf8
  ru_UA
  ru_UA.utf8
  se_NO
  sk_SK
  sk_SK.utf8
  sl_SI
  sl_SI.utf8
  sq_AL
  sq_AL.utf8
  sr_YU
  sr_YU@cyrillic
  sr_YU.utf8
  sr_YU.utf8@cyrillic
  sv_FI
  sv_FI@euro
  sv_FI.utf8
  sv_FI.utf8@euro
  sv_SE
  sv_SE.iso885915
  sv_SE.utf8
  ta_IN
  te_IN
  tg_TJ
  th_TH
  th_TH.utf8
  tl_PH
  tr_TR
  tr_TR.utf8
  uk_UA
  uk_UA.utf8
  ur_PK
  uz_UZ
  vi_VN
  vi_VN.tcvn
  wa_BE
  wa_BE@euro
  yi_US
  zh_CN
  zh_CN.gb18030
  zh_CN.gbk
  zh_CN.utf8
  zh_HK
  zh_HK.utf8
  zh_TW
  zh_TW.euctw
  zh_TW.utf8
  

• `locale` displays environmental variables that impact how locale("") will be deduced.

  LANG=en_US
  LC_CTYPE="en_US"
  LC_NUMERIC="en_US"
  LC_TIME="en_US"
  LC_COLLATE="en_US"
  LC_MONETARY="en_US"
  LC_MESSAGES="en_US"
  LC_PAPER="en_US"
  LC_NAME="en_US"
  LC_ADDRESS="en_US"
  LC_TELEPHONE="en_US"
  LC_MEASUREMENT="en_US"
  LC_IDENTIFICATION="en_US"
  LC_ALL=
  

From Josuttis, p. 697-698, which says, that "there is only *one* relation (of the C++ locale mechanism) to the C locale mechanism: the global C locale is modified if a named C++ locale object is set as the global locale" (emphasis Paolo), that is:

affects the C functions as if the following call was made:

On the other hand, there is *no* viceversa, that is, calling setlocale has *no* whatsoever on the C++ locale mechanism, in particular on the working of locale(""), which constructs the locale object from the environment of the running program, that is, in practice, the set of LC_ALL, LANG, etc. variable of the shell.

4. Design

The major design challenge is fitting an object-orientated and non-global locale design ontop of POSIX and other relevant stanards, which include the Single Unix (nee X/Open.)

Because POSIX falls down so completely, portibility is an issue.

5. Examples

• testsuite/22_locale/all

6. Unresolved Issues

• locale initialization: at what point does _S_classic, _S_global get initialized? Can named locales assume this initialization has already taken place?
• document how named locales error check when filling data members. Ie, a fr_FR locale that doesn't have numpunct::truename(): does it use "true"? Or is it a blank string? What's the convention?
• explain how locale aliasing happens. When does "de_DE" use "de" information? What is the rule for locales composed of just an ISO language code (say, "de") and locales with both an ISO language code and ISO country code (say, "de_DE").
• what should non-required facet instantiations do? If the generic implemenation is provided, then how to end-users provide specializations?

7. Acknowledgments

8. Bibliography / Referenced Documents

Drepper, Ulrich, Numerous, late-night email correspondence

ISO/IEC 14882:1998 Programming languages - C++

ISO/IEC 9899:1999 Programming languages - C

Langer, Angelika and Klaus Kreft, Standard C++ IOStreams and Locales, Advanced Programmer's Guide and Reference, Addison Wesley Longman, Inc. 2000

Stroustrup, Bjarne, Appendix D, The C++ Programming Language, Special Edition, Addison Wesley, Inc. 2000

System Interface Definitions, Issue 6 (IEEE Std. 1003.1-200x) The Open Group/The Institute of Electrical and Electronics Engineers, Inc. http://www.opennc.org/austin/docreg.html