Re: Ada to C Question

[Hyman Rosen <hyrosen@mail.com>]

MPowell wrote:
> Of course in C (porting to C) declarations above don't work.  As far
> as the typedef sees 'it' some parameters are just re-declarations.

The right way to do these in C++ is as follows:
     struct SET_RESET_TYPE { enum { Set, Reset } e; };
     struct RESET_SET_TYPE { enum { Reset, Set } e; };
     // etc.
and qualify the literals with the appropriate type, eg.,
     SET_RESET_TYPE::Set

> I'm not sure how I could handle 'generics' in C.  So now:
> 
> generic
>  type ELEMENT is private;
>  Initial_Element : ELEMENT;
> 
> package Protected_Msg is 
>   function Read return ELEMENT;
>   procedure Push (E : Element);
> end Protected_Msg;
> 
> the package body follows.

Again, use C++. Things may vary depending on how Initial_Element is used.
     template <typename ELEMENT>
     struct Protected_Msg {
         static ELEMENT Read();
         static void Push(ELEMENT);
         static ELEMENT Initial_Element();
     };

> type TEMPERATURE is Float;
> subtype TEMP_RANGE is TEMPERATURE range -50 .. 50;
> 
> I like subtypes in Ada but no way to handle subtypes in C so I have to
> use #define max and min and use if statments.

Again, using C++ you could define a class which would do the range checks.