Language features

C code must compile under either a conforming ANSI C compiler OR an original Kernighan & Ritchie C compiler. Therefore, the __STDC__ macro must be used to select alternative code where necessary.. ( example )

Code should compile without warnings under an ANSI C compiler such as gcc with all warnings enabled.

Parameters and Arguments

The PARAMS(()) macro is used to give a format parameter list in a declataion so that it will be suppressed if the compiler is not standard C - see example .. The ARGS1 macro is for the declaration of the implementation, taking first the type then the argument name. For n arguments, macros ARGn exists taking 2n arguments each.

#endif

Do put the ending condition in a comment. Don't put it as code - it won't pass all compilers.

#elif

Don't use it. Basic cpp doesn't know it.

#preprocessor statements

DON'T indent any preprocessor statements. They must (for some compilers) begin in column 1.

const

This keyword does not exist in K&R C, so use the macro CONST which expands to "const" under standard C and nothing otherwise. -- See HTUtils.h