std::messages_byname

 

C++

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Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

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Technical Specifications

 

Localizations library

Locales and facets
locale
use_facet	has_facet
Character classification
isspace isblank (C++11) iscntrl isupper islower isalpha	isdigit ispunct isxdigit isalnum isprint isgraph
Conversions
toupper tolower	wstring_convert (C++11) wbuffer_convert (C++11)
Facet category base classes
ctype_base codecvt_base messages_base	time_base money_base
Facet categories
ctype ctype<char> codecvt collate messages time_get time_put	num_get num_put numpunct money_get money_put moneypunct
Locale-specific facets
ctype_byname codecvt_byname messages_byname collate_byname	time_get_byname time_put_byname numpunct_byname moneypunct_byname
Code conversion facets
codecvt_utf8 (C++11) codecvt_utf16 (C++11)	codecvt_utf8_utf16 (C++11) codecvt_mode (C++11)
C locale
setlocale localeconv lconv	LC_ALLLC_COLLATELC_CTYPELC_MONETARYLC_NUMERICLC_TIME

 

Defined in header <locale>
template< class CharT > class messages_byname : public std::messages<CharT>;

std::messages_byname is a std::messages facet which encapsulates retrieval of strings from message catalogs of the locale specified at its construction.

Two specializations are provided by the standard library

Defined in header <locale>
std::messages_byname<char>	narrow/multibyte message catalog access
std::messages_byname<wchar_t>	wide string message catalog access

Member types

Member type	Definition
catalog	std::messages_base<CharT>::catalog
string_type	std::basic_string<CharT>

Member functions

(constructor)	constructs a new messages_byname facet (public member function)
(destructor)	destroys a messages_byname facet (protected member function)

std::messages_byname::messages_byname

explicit messages_byname( const char* name, std::size_t refs = 0 );
explicit messages_byname( const std::string& name, std::size_t refs = 0 );		(since C++11)

Constructs a new std::messages_byname facet for a locale with name.

refs is used for resource management: if refs == 0, the implementation destroys the facet, when the last std::locale object holding it is destroyed. Otherwise, the object is not destroyed.

Parameters

name	-	the name of the locale
refs	-	the number of references that link to the facet

std::messages_byname::~messages_byname

protected: ~messages_byname();

Destroys the facet.

Inherited from std::messages

Member types

Member type	Definition
char_type	charT
string_type	std::basic_string<charT>

Member objects

Member name	Type
id (static)	std::locale::id

Member functions

open	invokes do_open (public member function of std::messages<CharT>)
get	invokes do_get (public member function of std::messages<CharT>)
close	invokes do_close (public member function of std::messages<CharT>)

Protected member functions

do_open [virtual]	opens a named message catalog (virtual protected member function of std::messages<CharT>)
do_get [virtual]	retrieves a message from an open message catalog (virtual protected member function of std::messages<CharT>)
do_close [virtual]	closes a message catalog (virtual protected member function of std::messages<CharT>)

Example

Run this code

#include <iostream>
#include <locale>
 
void try_with(const std::locale& loc)
{
    const std::messages<char>& facet = std::use_facet<std::messages<char> >(loc)
;
    std::messages<char>::catalog cat = facet.open("sed", std::cout.getloc());
    if(cat < 0 )
        std::cout << "Could not open \"sed\" message catalog\n";
    else
        std::cout << "\"No match\" "
                  << facet.get(cat, 0, 0, "No match") << '\n'
                  << "\"Memory exhausted\" " 
                  << facet.get(cat, 0, 0, "Memory exhausted") << '\n';
    facet.close(cat);
}
int main()
{
    std::locale loc("en_US.utf8");
    std::cout.imbue(loc);
 
    try_with(std::locale(loc, new std::messages_byname<char>("de_DE.utf8")));
    try_with(std::locale(loc, new std::messages_byname<char>("fr_FR.utf8")));
    try_with(std::locale(loc, new std::messages_byname<char>("ja_JP.utf8")));
}

Possible output:

"No match" Keine Übereinstimmung
"Memory exhausted" Speicher erschöpft
"No match" Pas de concordance
"Memory exhausted" Mémoire épuisée
"No match" 照合しません
"Memory exhausted" メモリーが足りません

See also

messages

implements retrieval of strings from message catalogs (class template)