Class extension

include/covscript/core/core.hpp:1200–1229

	} // namespace dll

	class extension final : public name_space {
		void *mHandle;

	public:
		extension() = delete;

		extension(const extension &) = delete;

		virtual ~extension() = default;

		static inline int truncate(int n, int m)
		{
			return n == 0 ? 0 : n / int(std::pow(10, (std::max) (int(std::log10(std::abs(n))) - (std::max) (m, 0) + 1, 0)));
		}

		explicit extension(std::string_view path)
		{
			mHandle = dll::open(path);
			dll::compatible_check_t dll_check = reinterpret_cast<dll::compatible_check_t>(dll::find_symbol(mHandle, dll::compatible_check));
			if (dll_check == nullptr || truncate(dll_check(), 4) != truncate(COVSCRIPT_ABI_VERSION, 4))
				throw runtime_error("Incompatible Extension. (Target ABI: " + std::to_string(dll_check()) +
				                    ", Current ABI: " + std::to_string(COVSCRIPT_ABI_VERSION) + ")");
			dll::main_entrance_t dll_main = reinterpret_cast<dll::main_entrance_t>(dll::find_symbol(mHandle, dll::main_entrance));
			if (dll_main != nullptr) {
				dll_main(this, current_process);
			}
			else
				throw runtime_error("Broken Extension.");
		}
	};

	var make_namespace(const namespace_t &);