On 23 Jan, 18:11, "Kasper Marstal" <lifesucksandthenyou...@gmail.com>
wrote:

You need to take particular care when writing C and C++ programs
that are supposed to be portable. Both languages have a core
that is standardized, and that at leat in principle should
compile on every platform.

However, there are many ways to depart from the standard,
either by leaving out standardized features (or rather,
compiler vendors have not yet implemented recently
standardized features), or by adding platform- or compiler-
specific libraries or features.

There are also variations on how strict any particular
compiler will be with respect to syntax and warnings, etc.

Once you are aware of these kinds of things, there are a
few guidelines you can use to minimize such problems:

1) Strictly stick to standardized C or C++ code. Don't
   use compiler-, OS- or platform-specific libraries,
   as these will get you into trouble when you attempt
   to port.
2) Learn your compiler. Most compilers have switches and
   directives that either disable non-standard features
   and / or forces the compiler to accept only standardized
   code.
3) Compile the same code on several systems and compilers.
   What one compiler accepts, another will reject. Like what
   probably is the case in your code.

In addition, use type declarations like size_t, ptrdiff_t
and so on, instead of int, unsigned int, long int etc.
These are the kinds of things that are almost certain to
cause trouble when porting between platforms.

Rune