std::messages<CharT>::get, std::messages<CharT>::do_get
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std::messages
Member functions
messages::getmessages::do_get
Defined in header
<locale>
public:
string_type get( catalog cat, int set, int msgid, const string_type& dfault ) const;
(1)
string_type get( catalog cat, int set, int msgid, const string_type& dfault ) const;
protected:
virtual string_type do_get( catalog cat, int set, int msgid, const string_type& dfault ) const;
(2)
virtual string_type do_get( catalog cat, int set, int msgid, const string_type& 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.
Contents
[edit] Parameters
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
[edit] Return value
The message from the catalog or a copy of dfault if none was found.
[edit] 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.
[edit] 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