Standard library header <locale>

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Standard Library header files

Language Support
<cstddef> <limits> <climits>	<cfloat> <cstdint> <new>	<typeinfo> <exception> <initializer_list>	<csignal> <csetjmp> <cstdarg>
Diagnostics
<stdexcept>	<cassert>	<cerrno>	<system_error>
General utilities
<utility> <memory> <memory_resource> <scoped_allocator>	<tuple> <optional> <any> <variant>	<bitset> <functional> <type_traits> <ratio>	<chrono> <ctime> <typeindex> <cstdlib>
Strings
<string> <string_view>	<cctype> <cwctype>	<cwchar> <cuchar>	<cstring>
Localization
<locale>	<codecvt>	<clocale>
Containers
<array> <deque> <vector>	<forward_list> <list>	<map> <set> <queue>	<unordered_map> <unordered_set> <stack>
Iterators
<iterator>
Algorithms
<algorithm>	<execution_policy>
Numerics
<complex> <random>	<valarray> <numeric>	<cfenv> <cmath>
Input/Output
<iosfwd> <iostream> <ios>	<streambuf> <istream> <ostream>	<iomanip> <sstream> <fstream>	<filesystem> <cstdio> <cinttypes>
Regular expressions
<regex>
Thread support
<thread> <atomic>	<mutex> <shared_mutex>	<condition_variable> <future>
C compatibility
<ciso646> <cstdalign>	<cstdbool> <ccomplex>	<ctgmath>

 

This header is part of the localization library.

Classes
locale	set of polymorphic facets that encapsulate cultural differences (class)
String and stream conversions
wstring_convert (C++11)(deprecated in C++17)	performs conversions between a wide string and a byte string (class template)
wbuffer_convert (C++11)(deprecated in C++17)	performs conversion between a byte stream buffer and a wide stream buffer (class template)
Facet category base classes
ctype_base	defines character classification categories (class)
codecvt_base	defines character conversion errors (class)
messages_base	defines messages catalog type (class)
time_base	defines date format constants (class)
money_base	defines monetary formatting patterns (class)
Facet categories
ctype	defines character classification tables (class template)
ctype<char>	specialization of std::ctype for type char (class template specialization)
codecvt	converts between character encodings, including UTF-8, UTF-16, UTF-32 (class template)
collate	defines lexicographical comparison and hashing of strings (class template)
messages	implements retrieval of strings from message catalogs (class template)
time_get	parses time/date values from an input character sequence into struct std::tm (class template)
time_put	formats contents of struct std::tm for output as character sequence (class template)
num_get	parses numeric values from an input character sequence (class template)
num_put	formats numeric values for output as character sequence (class template)
numpunct	defines numeric punctuation rules (class template)
money_get	parses and constructs a monetary value from an input character sequence (class template)
money_put	formats a monetary value for output as a character sequence (class template)
moneypunct	defines monetary formatting parameters used by std::money_get and std::money_put (class template)
Locale-specific facet categories
ctype_byname	represents the system-supplied std::ctype for the named locale (class template)
codecvt_byname	represents the system-supplied std::codecvt for the named locale (class template)
messages_byname	represents the system-supplied std::messages for the named locale (class template)
collate_byname	represents the system-supplied std::collate for the named locale (class template)
time_get_byname	represents the system-supplied std::time_get for the named locale (class template)
time_put_byname	represents the system-supplied std::time_put for the named locale (class template)
numpunct_byname	represents the system-supplied std::numpunct for the named locale (class template)
moneypunct_byname	represents the system-supplied std::moneypunct for the named locale (class template)
Functions
Locales and facets
use_facet	obtains a facet from a locale (function template)
has_facet	checks if a locale implements a specific facet (function template)
Character classification
isspace(std::locale)	checks if a character is classified as whitespace by a locale (function template)
isblank(std::locale) (C++11)	checks if a character is classified as a blank character by a locale (function template)
iscntrl(std::locale)	checks if a character is classified as a control character by a locale (function template)
isupper(std::locale)	checks if a character is classified as uppercase by a locale (function template)
islower(std::locale)	checks if a character is classified as lowercase by a locale (function template)
isalpha(std::locale)	checks if a character is classified as alphabetic by a locale (function template)
isdigit(std::locale)	checks if a character is classified as a digit by a locale (function template)
ispunct(std::locale)	checks if a character is classified as punctuation by a locale (function template)
isxdigit(std::locale)	checks if a character is classified as a hexadecimal digit by a locale (function template)
isalnum(std::locale)	checks if a character is classified as alphanumeric by a locale (function template)
isprint(std::locale)	checks if a character is classified as printable by a locale (function template)
isgraph(std::locale)	checks if a character is classfied as graphical by a locale (function template)
Character conversions
toupper(std::locale)	converts a character to uppercase using the ctype facet of a locale (function template)
tolower(std::locale)	converts a character to lowercase using the ctype facet of a locale (function template)

Synospis

namespace std {
 
    // locale:
    class locale;
    template <class Facet> const Facet& use_facet(const locale&);
    template <class Facet> bool has_facet(const locale&) noexcept;
 
    // convenience interfaces:
    template <class charT> bool isspace (charT c, const locale& loc);
    template <class charT> bool isprint (charT c, const locale& loc);
    template <class charT> bool iscntrl (charT c, const locale& loc);
    template <class charT> bool isupper (charT c, const locale& loc);
    template <class charT> bool islower (charT c, const locale& loc);
    template <class charT> bool isalpha (charT c, const locale& loc);
    template <class charT> bool isdigit (charT c, const locale& loc);
    template <class charT> bool ispunct (charT c, const locale& loc);
    template <class charT> bool isxdigit(charT c, const locale& loc);
    template <class charT> bool isalnum (charT c, const locale& loc);
    template <class charT> bool isgraph (charT c, const locale& loc);
    template <class charT> charT toupper(charT c, const locale& loc);
    template <class charT> charT tolower(charT c, const locale& loc);
    template <class Codecvt, class Elem = wchar_t,
              class Wide_alloc = std::allocator<Elem>,
        class Byte_alloc = std::allocator<char> > class wstring_convert;
    template <class Codecvt, class Elem = wchar_t,
              class Tr = char_traits<Elem>> class wbuffer_convert;
 
    // ctype:
    class ctype_base;
    template <class charT> class ctype;
    template <>            class ctype<char>; // specialization
    template <class charT> class ctype_byname;
    class codecvt_base;
    template <class internT, class externT, class stateT> class codecvt;
    template <class internT, class externT, class stateT> class codecvt_byname;
 
    // numeric:
    template <class charT,	class	InputIterator = istreambuf_iterator<charT> > class num_get;
    template <class charT,	class	OutputIterator = osterambuf_iterator<charT> > class num_put;
    template <class charT>	class	numpunct;
    template <class charT>	class	numpunct_byname;
 
    // collation:
    template <class charT> class collate;
    template <class charT> class collate_byname;
 
    // date and time:
    class time_base;	
    template <class charT, class InputIterator = istreambuf_iterator<charT> >
        class time_get;	
    template <class charT, class InputIterator> = istreambuf_iterator<charT> >
        class time_get_byname;	
    template <class charT, class OutputIterator> = ostreambuf_iterator<charT> >
        class time_put;	
    template <class charT, class OutputIterator> = ostreambuf_iterator<charT> >
        class time_put_byname;	
 
    // money:	
    class money_base;	
    template <class charT, class InputIterator = istreambuf_iterator<charT> > > 
        class money_get;
    template <class charT, class OutputIterator = ostreambuf_iterator<charT> > > 
        class money_put;
    template <class charT, bool Intl = false> class moneypunct;
    template <class charT, bool Intl = false> class moneypunct_byname;
 
    // message retrieval:
    class messages_base;
    template <class charT> class messages;
    template <class charT> class messages_byname;
}

Class std::locale

class locale
{
public:
    // types:
    class facet;
    class id;
    typedef int category;
    static const category // values assigned here are for exposition only
        none    = 0,
        collate = 0x010, 
        ctype   = 0x020,
        monetary= 0x040, 
        numeric = 0x080,
        time    = 0x100, 
        messages= 0x200,
        all = collate | ctype | monetary | numeric | time | messages;
 
    // construct/copy/destroy:
    locale() noexcept;
    locale(const locale& other) noexcept;
    explicit locale(const char* std_name);
    explicit locale(const string& std_name);
    locale(const locale& other, const char* std_name, category);
    locale(const locale& other, const string& std_name, category);
    template <class Facet> locale(const locale& other, Facet* f);
    locale(const locale& other, const locale& one, category);
    ~locale();
 
    // not virtual
    const locale& operator=(const locale& other) noexcept;
    template <class Facet> locale combine(const locale& other) const;
 
    // locale operations:
    basic_string<char>
    name() const;
    bool operator==(const locale& other) const;
    bool operator!=(const locale& other) const;
    template <class charT, class traits, class Allocator>
    bool operator()(const basic_string<charT,traits,Allocator>& s1,
                    const basic_string<charT,traits,Allocator>& s2) const;
 
    // global locale objects:
    static
    locale global(const locale&);
    static const locale& classic();
};

Class std::ctype_base

class ctype_base {
public:
    typedef /*T*/ mask;
 
    // numeric values are for exposition only.
    static const mask space = 1 << 0;
    static const mask print = 1 << 1;
    static const mask cntrl = 1 << 2;
    static const mask upper = 1 << 3;
    static const mask lower = 1 << 4;
    static const mask alpha = 1 << 5;
    static const mask digit = 1 << 6;
    static const mask punct = 1 << 7;
    static const mask xdigit= 1 << 8;
    static const mask blank = 1 << 9;
    static const mask alnum = alpha | digit;
    static const mask graph = alnum | punct;
 
};

Class std::ctype

template <class charT>
class ctype : public locale::facet, public ctype_base
{
public:
    typedef charT char_type;
 
    explicit ctype(size_t refs = 0);
 
    bool is(mask m, charT c) const;
    const charT* is(const charT* low, const charT* high, mask* vec) const;
    const charT* scan_is(mask m,
                         const charT* low, const charT* high) const;
    const charT* scan_not(mask m,
                          const charT* low, const charT* high) const;
 
    charT           toupper(charT c) const;
    const charT*    toupper(charT* low, const charT* high) const;
    charT           tolower(charT c) const;
    const charT*    tolower(charT* low, const charT* high) const;
 
    charT       widen(char c) const;
    const char* widen(const char* low, const char* high, charT* to) const;
    char        narrow(charT c, char dfault) const;
    const charT*narrow(const charT* low, const charT*, char dfault,
                        char* to) const;
 
    static locale::id id;
 
protected:
    ~ctype();
    virtual bool do_is(mask m, charT c) const;
    virtual const charT* do_is(const charT* low, const charT* high,
                               mask* vec) const;
    virtual const charT* do_scan_is(mask m,
                                    const charT* low, const charT* high) const;
    virtual const charT* do_scan_not(mask m,
                                     const charT* low, const charT* high) const;
 
    virtual charT do_toupper(charT) const;
    virtual const charT* do_toupper(charT* low, const charT* high) const;
    virtual charT do_tolower(charT) const;
    virtual const charT* do_tolower(charT* low, const charT* high) const;
    virtual charT do_widen(char) const;
    virtual const char*  do_widen(const char* low, const char* high,
                                  charT* dest) const;
    virtual char do_narrow(charT, char dfault) const;
    virtual const charT* do_narrow(const charT* low, const charT* high,
                                   char dfault, char* dest) const;
};

Class std::ctype_byname

template <class charT>
class ctype_byname : public ctype<charT> {
public:
    typedef typename ctype<charT>::mask mask;
    explicit ctype_byname(const char*, size_t refs = 0);
    explicit ctype_byname(const string&, size_t refs = 0);
    protected:
    ~ctype_byname();
};

Class std::ctype<char>

template <> class ctype<char>
    : public locale::facet, public ctype_base
{
public:
    typedef char char_type;
    explicit ctype(const mask* tab = 0, bool del = false,
                   size_t refs = 0);
    bool is(mask m, char c) const;
    const char* is(const char* low, const char* high, mask* vec) const;
    const char* scan_is (mask m,
                         const char* low, const char* high) const;
    const char* scan_not(mask m,
                         const char* low, const char* high) const;
    char        toupper(char c) const;
    const char* toupper(char* low, const char* high) const;
    char        tolower(char c) const;
    const char* tolower(char* low, const char* high) const;
    char        widen(char c) const;
    const char* widen(const char* low, const char* high, char* to) const;
    char        narrow(char c, char dfault) const;
    const char* narrow(const char* low, const char* high, char dfault,
                       char* to) const;
 
    static locale::id id;
 
    static const size_t table_size = implementation-defined;
    const mask* table() const noexcept;
    static const mask* classic_table() noexcept;
 
protected:
    ~ctype();
    virtual char        do_toupper(char c) const;
    virtual const char* do_toupper(char* low, const char* high) const;
    virtual char        do_tolower(char c) const;
    virtual const char* do_tolower(char* low, const char* high) const;
    virtual char        do_widen(char c) const;
    virtual const char* do_widen(const char* low,
                                 const char* high,
                                 char* to) const;
    virtual char        do_narrow(char c, char dfault) const;
    virtual const char* do_narrow(const char* low,
                                  const char* high,
                                  char dfault, char* to) const;
};

Class std::codecvt_base

class codecvt_base
{
public:
    enum result { ok, partial, error, noconv };
};

Class std::codecvt

template <class internT, class externT, class stateT>
class codecvt : public locale::facet, public codecvt_base
{
public:
        typedef internT intern_type;
        typedef externT extern_type;
        typedef stateT state_type;
        explicit codecvt(size_t refs = 0);
        result out(stateT& state,
                   const internT* from, const internT* from_end, 
                   const internT*& from_next,
                   externT* to, externT* to_end, externT*& to_next) const;
        result unshift(stateT& state, externT* to,
                       externT* to_end, externT*& to_next) const;
        result in(stateT& state,
                  const externT* from, const externT* from_end, 
                  const externT*& from_next,
                  internT* to,
                  internT* to_end, internT*& to_next) const;
        int encoding() const noexcept;
        bool always_noconv() const noexcept;
        int length(stateT&, const externT* from, const externT* end,
                   size_t max) const;
        int max_length() const noexcept;
        static locale::id id;
protected:
        ~codecvt();
        virtual result do_out(stateT& state,
                              const internT* from, const internT* from_end, 
                              const internT*& from_next,
                              externT* to,
                              externT* to_end, externT*& to_next) const;
        virtual result do_in(stateT& state,
                             const externT* from, const externT* from_end, 
                             const externT*& from_next,
                             internT* to,
                             internT* to_end, internT*& to_next) const;
        virtual result do_unshift(stateT& state,
                                  externT* to,
                                  externT* to_end, externT*& to_next) const;
        virtual int do_encoding() const noexcept;
        virtual bool do_always_noconv() const noexcept;
        virtual int do_length(stateT&, const externT* from,
                              const externT* end, size_t max) const;
        virtual int do_max_length() const noexcept;
};

Class std::codecvt_byname

template <class internT, class externT, class stateT>
class codecvt_byname : public codecvt<internT, externT, stateT> {
public:
    explicit codecvt_byname(const char*, size_t refs = 0);
    explicit codecvt_byname(const string&, size_t refs = 0);
protected:
    ~codecvt_byname();
};

Class std::num_get

template <class charT, class InputIterator = istreambuf_iterator<charT> >
class num_get : public locale::facet
{
public:
    typedef charT           char_type;
    typedef InputIterator   iter_type;
    explicit num_get(size_t refs = 0);
    iter_type get(iter_type in, iter_type end, ios_base&,
                  ios_base::iostate& err, bool& v) const;
    iter_type get(iter_type in, iter_type end, ios_base& ,
                  ios_base::iostate& err, long& v) const;
    iter_type get(iter_type in, iter_type end, ios_base& ,
                  ios_base::iostate& err, long long& v) const;
    iter_type get(iter_type in, iter_type end, ios_base&,
                  ios_base::iostate& err, unsigned short& v) const;
    iter_type get(iter_type in, iter_type end, ios_base&,
                  ios_base::iostate& err, unsigned int& v) const;
    iter_type get(iter_type in, iter_type end, ios_base&,
                  ios_base::iostate& err, unsigned long& v) const;
    iter_type get(iter_type in, iter_type end, ios_base& ,
                  ios_base::iostate& err, unsigned long long& v) const;
    iter_type get(iter_type in, iter_type end, ios_base&,
                  ios_base::iostate& err, float& v) const;
    iter_type get(iter_type in, iter_type end, ios_base&,
                  ios_base::iostate& err, double& v) const;
    iter_type get(iter_type in, iter_type end, ios_base&,
                  ios_base::iostate& err, long double& v) const;
    iter_type get(iter_type in, iter_type end, ios_base&,
                  ios_base::iostate& err, void*& v) const;
 
    static locale::id id;
 
 
protected:
    ~num_get();
 
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, bool& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, long& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, long long& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, unsigned short& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, unsigned int& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, unsigned long& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, unsigned long long& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, float& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, double& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, long double& v) const;
    virtual iter_type do_get(iter_type, iter_type, ios_base&,
                             ios_base::iostate& err, void*& v) const;
};