Learning that you can use unions in C for grouping things into namespaces

Re:Learning that you can use unions in C for grouping things... by shultays on Sunday August 01, 2021 @09:36PM (#28032015)

   The optimizer will delete bar() if FOO is a manifest constant that is not 3.

Yes, but the compiler won't delete it and complain if bar is not defined. if constexpr is not a direct replacement for if macro

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Re:Learning that you can use unions in C for grouping things... by WalterBright on Sunday August 01, 2021 @11:28PM (#28032575)

> the compiler won't delete it and complain if bar is not defined

    extern void bar();

will define it to the satisfaction of the compiler. The linker won't complain if the compiler removes the call to it.

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Re:Learning that you can use unions in C for grouping things... by shultays on Monday August 02, 2021 @05:27AM (#28034565)

And then you have the issue of not having types. consider this

  void my_bar_class_type::bar(my_bar_type<my_bar_type_2>::my_bar_inside_type paramater);

and you are calling something like

   myObject->bar(mySecondObject.getWhatever());

You have to mock up like everything

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Re:Learning that you can use unions in C for grouping things... by WalterBright on Monday August 02, 2021 @02:05PM (#28040371)

Or go up an abstraction layer so the type details are not needed.

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