I use gettext for internalization. I define a static and a non-static string. The string only gets translated the second time I wrapp it with __(). In my understanding, the string should already be translated upon definition.

How do I achieve that the string is translated in the definition?

main.cpp

#include <iostream>
#include <string>
#include <libintl.h>

#define __(String) gettext(String)

class A {
public:
    static const std::string BASE_PCB;
};

const std::string A::BASE_PCB = __("BasePCB");

int main() {
    std::string BASE_PCB_2 = __("BasePCB2");

    const std::string path = "/usr/local/share/locale";
    std::cout << "Locale path: " << path << std::endl;

    setlocale(LC_ALL, "fr_CH.utf8");
    bindtextdomain("example", path.c_str());
    textdomain("example");

    std::cout << "Locale: " << setlocale(LC_ALL, nullptr) << std::endl;

    std::cout << "1. Translation: " << A::BASE_PCB.c_str() << std::endl;
    std::cout << "2. Translation with __: " << __(A::BASE_PCB.c_str()) << std::endl;
    std::cout << "3. Translation: " << BASE_PCB_2 << std::endl;
    std::cout << "4. Translation with __: " << __(BASE_PCB_2.c_str()) << std::endl;
    return 0;
}

fr.po

#: main.cpp:12
msgid "BasePCB"
msgstr "Base PCB"

#: main.cpp:15
msgid "BasePCB2"
msgstr "Base PCB 2"

*.mo generation and placement

msgfmt fr.po -o example.mo
cp example.mo /usr/local/share/locale/fr/LC_MESSAGES/example.mo

CMakeLists.txt

cmake_minimum_required(VERSION 3.8)

project (
 "CppInternationalization"
 VERSION 1.0.0
 LANGUAGES CXX
)

# Using C++20

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

add_executable(${PROJECT_NAME} "main.cpp")

# add libintl

find_package(Intl REQUIRED)
target_link_libraries(${PROJECT_NAME} PUBLIC ${Intl_LIBRARY})
target_include_directories(${PROJECT_NAME} PUBLIC ${Intl_INCLUDE_DIRS})

Execution

mkdir build
cmake .. && cmake --build . && ./CppInternationalization

OUTPUT

Locale path: /usr/local/share/locale
Locale: fr_CH.utf8
1. Translation: BasePCB  # <- Expected 'Base PCB'
2. Translation with __: Base PCB
3. Translation: BasePCB2  # <- Expected 'Base PCB 2'
4. Translation with __: Base PCB 2