C++ Class or Struct compatiblity with C struct

Question

Is it possible to write a C++ class or struct that is fully compatible with C struct. From compatibility I mean size of the object and memory locations of the variables. I k

Answer 1

Yes.

• Use the same types in the same order in both languages
• Make sure the class doesn't have anything virtual in it (so you don't get a vtable pointer stuck on the front)
• Depending on the compilers used you may need to adjust the structure packing (usually with pragmas) to ensure compatibility.

(edit)

• Also, you must take care to check the sizeof() the types with your compilers. For example, I've encountered a compiler that stored shorts as 32 bit values (when most will use 16). A more common case is that an int will usually be 32 bits on a 32-bit architecture and 64 bits on a 64-bit architecture.