fix reflect-cpp compilation when msgpack is enabled

[mirageAlchemy]

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[mirageAlchemy]

i would actually like to include some trivial tests for msgpack behaviour, maybe like this:

        
        assert(package:check_cxxsnippets({test = [[
            #include <rfl/msgpack.hpp>
            #include <rfl.hpp>
            struct Person {
                std::string first_name;
                std::string last_name;
                int age;
            };
            const auto homer = Person{.first_name = "Homer",
                                      .last_name = "Simpson",
                                      .age = 45};
            void test() {
                const std::vector<char> msgpack_data = rfl::msgpack::write(homer);
                auto homer2 = rfl::msgpack::read<Person>(msgpack_data).value();
            }   
        ]]}, {configs = {languages = "c++20", msgpack = true}}))

But I am not quite sure it is advocated?

[waruqi]

i would actually like to include some trivial tests for msgpack behaviour, maybe like this:

        
        assert(package:check_cxxsnippets({test = [[
            #include <rfl/msgpack.hpp>
            #include <rfl.hpp>
            struct Person {
                std::string first_name;
                std::string last_name;
                int age;
            };
            const auto homer = Person{.first_name = "Homer",
                                      .last_name = "Simpson",
                                      .age = 45};
            void test() {
                const std::vector<char> msgpack_data = rfl::msgpack::write(homer);
                auto homer2 = rfl::msgpack::read<Person>(msgpack_data).value();
            }   
        ]]}, {configs = {languages = "c++20", msgpack = true}}))

But I am not quite sure it is advocated?

How is it different from the current test? As long as the test code is kept as short as possible, it is allowed to add some other tests as appropriate.

[mirageAlchemy]

Current test only covers a subset of all configuration cases, that is only json support is enabled. The test I provided above has msgpack configured, so ensures any possible upgrade does not break msgpack support. I was hesitant to add it because I am not sure if I should add the test only when the user demands msgpack explicitly in config, or should I include it by default so it is checked by CI.

[waruqi]

Current test only covers a subset of all configuration cases, that is only json support is enabled. The test I provided above has msgpack configured, so ensures any possible upgrade does not break msgpack support. I was hesitant to add it because I am not sure if I should add the test only when the user demands msgpack explicitly in config, or should I include it by default so it is checked by CI.

we can test it when msgpack is enabled.

if package:config("msgpack") then
    -- test it
end

[mirageAlchemy]

I have added a test only when msgpack is specified by the user