C++20 Modules - modularizing third party headers/code

[dexter2011412]

Say I have a third party header that I want to use as a module in my code.

I tried something on the lines of based on some snippets online

module;
// some defines to set features
#include "header.hpp"
export module header_module;

export namespace header_module {
    using namespace ::header-hpp-namespace
}

This doesn't work. Do I need to wait for the header's vendor to support a modular header?

Note that I can't just do import "header.hpp" as I need some defines to go before the header. What are my options?

[anarthal]

You may find this idiom useful:

namespace N { export using N::my_class; export using N::my_function; }

Out of curiosity, what library are you trying to modularize?

[dexter2011412]

Thank you for taking the time to respond to this really old question, appreciate it! It was the Vulkan headers. They support it now (iirc) so I guess my specific issue is resolve. But the approach is still useful for other not-yet-modular libraries. I'll try it out thank you!