Can not use the modules feature from c++20 with Qt Creator and VS

[franco.amato]

Hi,
I am trying to use the modules feature (since C++20) but the compiler does not recognize it. I tried with VS2019 and VS2022 as compilers but the result is the same.

Below the content of my CMakeLists script:

cmake_minimum_required(VERSION 3.5)
 
project(Source LANGUAGES CXX)
 
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
add_executable(Source main.cpp
    AirlineTicket.cppm
    AirlineTicket.cpp)
 
target_compile_features(${PROJECT_NAME} PRIVATE cxx_std_20)
 
include(GNUInstallDirs)
install(TARGETS Source
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)

cmake_minimum_required(VERSION 3.5)

project(Source LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

add_executable(Source main.cpp
    AirlineTicket.cppm
    AirlineTicket.cpp)

target_compile_features(${PROJECT_NAME} PRIVATE cxx_std_20)

include(GNUInstallDirs)
install(TARGETS Source
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)

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And a very simple example of module:

export module airline_ticket;
 
import <string>;
 
export class AirlineTicket
{
public:
        AirlineTicket();
        ~AirlineTicket();
 
        double calculatePriceInDollars();
 
        std::string getPassengerName();
        void setPassengerName(std::string name);
 
        int getNumberOfMiles();
        void setNumberOfMiles(int miles);
 
        bool getHasEliteSuperRewardsStatus();
        void setHasEliteSuperRewardsStatus(bool status);
 
private:
        std::string m_passengerName;
        int m_numberOfMiles;
        bool m_hasEliteSuperRewardsStatus;
        std::string m_passengerName{ "Unknown Passenger" };
        int m_numberOfMiles{ 0 };
        bool m_hasEliteSuperRewardsStatus{ false };
};

export module airline_ticket;

import <string>;

export class AirlineTicket
{
public:
        AirlineTicket();
        ~AirlineTicket();

        double calculatePriceInDollars();

        std::string getPassengerName();
        void setPassengerName(std::string name);

        int getNumberOfMiles();
        void setNumberOfMiles(int miles);

        bool getHasEliteSuperRewardsStatus();
        void setHasEliteSuperRewardsStatus(bool status);

private:
        std::string m_passengerName;
        int m_numberOfMiles;
        bool m_hasEliteSuperRewardsStatus;
        std::string m_passengerName{ "Unknown Passenger" };
        int m_numberOfMiles{ 0 };
        bool m_hasEliteSuperRewardsStatus{ false };
};

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When I try to build the project, the compiler does not recognize absolutely anything about the module.
I import the module in AirlineTicket.cpp with the following code:

module airline_ticket;
 
using namespace std;
...more code...

module airline_ticket;

using namespace std;
...more code...

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Is there anything specific I have to do to write C++20 code?
Thanx

[OmarDay]

You can try this code

cmake_minimum_required(VERSION 3.20) # Ensure proper support for C++20 modules

project(Source LANGUAGES CXX)

# Set C++20 standard
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# Add executable and module files
add_executable(Source main.cpp AirlineTicket.cppm AirlineTicket.cpp)

# Enable C++20 features and experimental module support
target_compile_features(Source PRIVATE cxx_std_20)
target_compile_options(Source PRIVATE /experimental:module)

# Mark AirlineTicket.cppm as a C++ source file
set_source_files_properties(AirlineTicket.cppm PROPERTIES LANGUAGE CXX)

# Add installation rules (optional)
include(GNUInstallDirs)
install(TARGETS Source
LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)