NAME¶

std::messages::get,std::messages::do_get - std::messages::get,std::messages::do_get

Synopsis¶

Defined in header <locale>
public:
string_type get( catalog cat, int set, int msgid, const string_type& dfault ) (1)
const;
protected:
virtual string_type do_get( catalog cat, int set, int msgid, const string_type& (2)
dfault ) const;

1) Public member function, calls the protected virtual member function do_get of the
most derived class.

2) Obtains a message from the open message catalog cat using the values set, msgid
and dfault in implementation-defined manner. If the expected message is not found in
the catalog, returns a copy of dfault.

Parameters¶

cat - identifier of message catalog obtained from open() and not yet passed to
close()
set - implementation-defined argument, message set in POSIX
msgid - implementation-defined argument, message id in POSIX
dfault - the string to look up in the catalog (if the catalog uses string look-up)
and also the string to return in case of a failure

Return value¶

The message from the catalog or a copy of dfault if none was found.

Notes¶

On POSIX systems, this function call usually translates to a call to catgets(), and
the parameters set, msgid, and dfault are passed to catgets() as-is. In GNU
libstdc++, this function ignores set and msgid and simply calls GNU gettext(dfault)
in the required locale.

Example¶

The following example demonstrated retrieval of messages: on a typical GNU/Linux
system it reads from /usr/share/locale/de/LC_MESSAGES/sed.mo

// Run this code

#include <iostream>
#include <locale>

int main()
{
std::locale loc("de_DE.utf8");
std::cout.imbue(loc);
auto& facet = std::use_facet<std::messages<char>>(loc);
auto cat = facet.open("sed", loc);
if(cat < 0 )
std::cout << "Could not open german \"sed\" message catalog\n";
else
std::cout << "\"No match\" in German: "
<< facet.get(cat, 0, 0, "No match") << '\n'
<< "\"Memory exhausted\" in German: "
<< facet.get(cat, 0, 0, "Memory exhausted") << '\n';
facet.close(cat);
}

Possible output:¶

"No match" in German: Keine Übereinstimmung
"Memory exhausted" in German: Speicher erschöpft

See also¶