asyncFunction

extern(Windows) double foo(double n) nothrow @nogc { return 0; }
getWorksheetFunction!foo.shouldEqual(doubleToDoubleFunction("foo"));

extern(Windows) double bar(double n) nothrow @nogc { return 0; }
getWorksheetFunction!bar.shouldEqual(doubleToDoubleFunction("bar"));

extern(Windows) double foo(int) { return 0; }
getWorksheetFunction!foo.shouldThrowWithMessage("Unsupported function type double(int) for foo");

@Register(ArgumentText("my arg txt"), MacroType("macro"))
extern(Windows) double foo(double) nothrow;

auto expected = doubleToDoubleFunction("foo");
expected.argumentText = ArgumentText("my arg txt");
expected.macroType = MacroType("macro");

getWorksheetFunction!foo.shouldEqual(expected);

@Register(HelpTopic("I need somebody"), ArgumentText("my arg txt"))
extern(Windows) double foo(double) nothrow;

auto expected = doubleToDoubleFunction("foo");
expected.argumentText = ArgumentText("my arg txt");
expected.helpTopic = HelpTopic("I need somebody");

getWorksheetFunction!foo.shouldEqual(expected);