You can try to use a library offering cross-platform data types compatibility.
"The integral types C++ inherited from C are a cross-platform hazard. int, long and friends have different sizes on different platforms (32-bit and 64-bit on today's systems, maybe 128-bit later). For some applications it might seem irrelevant because they never approach the 32-bit limit (or rather 31-bit if you use unsigned integers), but if you serialize your objects on a 64-bit system and deserialize on a 32-bit system you might be unpleasantly surprised.
APR provides a set of typedefs for basic types that might be different on different platforms. These typedefs provide a guaranteed size and avoid the fuzzy built-in types. However, for some applications (mostly numerical) it is sometimes important to use the native machine word size (typically what int stands for) to achieve maximal performance."
Gigi SAYFAN - Building Your Own Plugin Framework (From http://philippe.ameline.free.fr/techytechy/071125_PluginFramework.htm)
