< cpp‎ | locale
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

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


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.


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



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

invokes do_open
(public member function of std::messages)
invokes do_get
(public member function of std::messages)
invokes do_close
(public member function of std::messages)

Protected member functions

opens a named message catalog
(virtual protected member function of std::messages)
retrieves a message from an open message catalog
(virtual protected member function of std::messages)
closes a message catalog
(virtual protected member function of std::messages)


#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 ="sed", std::cout.getloc());
    if(cat < 0 )
        std::cout << "Could not open \"sed\" message catalog\n";
        std::cout << "\"No match\" "
                  << facet.get(cat, 0, 0, "No match") << '\n'
                  << "\"Memory exhausted\" " 
                  << facet.get(cat, 0, 0, "Memory exhausted") << '\n';
int main()
    std::locale loc("en_US.utf8");
    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

implements retrieval of strings from message catalogs
(class template)