Getting started with Boost Locale's translate

Question

This might be a simple question but I'm struggling with it for quite a time, that's why I hope that one of you may help me.

I'm trying to get Boost locale's function translate to work. Referring this example code:

#include <boost/locale.hpp>
#include <iostream>

using namespace std;
using namespace boost::locale;

int main()
{
    generator gen;

    // Specify location of dictionaries
    gen.add_messages_path(".");
    gen.add_messages_domain("hello");

    // Generate locales and imbue them to iostream
    locale::global(gen(""));
    cout.imbue(locale());

    // Display a message using current system locale
    cout << translate("Hello World") << endl;
}

• Let's say I want to translate into german. Do I have to pass "de" like locale::global(gen("de")); ?

• I read something of *.po and *.mo files. Can someone explain me how this all works?

Thanks in advance.

Answer 1

Each locale is defined by a specific locale identifier, which contains a mandatory part (Language) and several optional parts (Country, Variant, keywords and character encoding of std::string). Boost.Locale uses the POSIX naming convention for locales, i.e. a locale is defined as language[_COUNTRY][.encoding][@variant], where lang is ISO-639 language name like "en" or "ru", COUNTRY is the ISO-3166 country identifier like "US" or "DE", encoding is the eight-bit character encoding like UTF-8 or ISO-8859-1, and variant is additional options for specializing the locale, like euro or calendar=hebrew, see Variant. Note that each locale should include the encoding in order to handle char based strings correctly. https://www.boost.org/doc/libs/1_48_0/libs/locale/doc/html/locale_gen.html

In your case it could be locale::global(gen("de_DE.UTF-8"));

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I would recommend you these sources for further information:

• https://www.boost.org/doc/libs/1_48_0/libs/locale/doc/html/main.html
• https://www.gnu.org/software/gettext/manual/html_node/gettext.html#gettext