i18n C++ Header Only Library

Why?

I wanted to make a super simple to use / beginer friendly library for internationalize c++ projects.

This library was created for internationalize Cyber Engine Tweaks.

This is a header only library, so you can just copy-paste the i18n.h to your project, include it and call it a day.

No need to build it.

This library can only provide basic functionalities.

If you want a more complete library please use ICU4C, Boost.Locale or GNU gettext.

If you don't want to deal with those complex libraries for a small project, you should use this library.

Requirements

At least C++17 (not sure):

• This library requires <format> from C++20 standard library. You need Visual Studio 2019 v16.10 or higher and change your project language standard to C++20 for it to work.

• Alternatively, you can use {fmt} library instead. You need to define I18N_USE_FMT in your project.

Usage

• Initialize

  // i18n::Init(std::filesystem::path localePath = "locales", std::string locale = "en-US", std::string defaultLocale = "en-US", std::string defaultNS = "default", std::string localeExtension = ".locale")
  i18n::Init();

• Switch locale

  i18n::SetLocale("zh-CN");

• Translate

  std::string str1 = i18n::Translate("Hello World!");
  std::string str2 = i18n::Translate("You catched {0:d} carrots in {1:d} seconds", 5, 2); // Using <format> from C++20 std or {fmt}

• Use namespace

  Locale file:

  ns: ns1
  msgid: Back
  msgstr: 返回
  
  ns: ns2
  msgid: Back
  msgstr: 背
  

  Code:

  i18n::TranslateN("ns1", "Back"); // Output 返回
  i18n::TranslateN("ns2", "Back"); // Output 背

Locale file format

The format is similar to GNU gettext's po file.

msgid: Hello World
msgstr: 你好世界

ns: ns1
msgid: Back
msgstr: 返回

ns: ns2
msgid: Back
msgstr: 背

Loading order

1. The library will search for a locale file for the default locale (locale path and default locale can be set with i18n::Init() function).

2. If the default locale file exists. The library will parse and load it.

3. If the default locale file doesn't exist. The i18n::Translate(std::string msgid) function will return the msgid.

4. After switching to another locale, if the msgid doesn't exist in current locale, i18n::Translate(std::string msgid) function will return the default locale string.

Build the example

Requirements

• The example project can only be built on Windows (because I'm loading fonts from Windows directory). The library is portable.

• Visual Studio 2019

• xmake

Build

1. Navigate to the repository using a command prompt.

2. Enter the following commands

   xmake -y
   xmake package
   xmake run

Todo

• Namespace support

• Cache the formated strings (To improve performance when using inside a loop)

• Plurals (This is more complicated than I thought)

• Locale file generation scripts (lua for xmake, and python)

• Add support for json files (i18next format)