question about wrapping asm instructions in classes

[boredevil]

I am rewriting my detour class atm, and was looking for a nice way to write instructions to the target functions ending up with the following:

pseudocode:

#pragma push(1)
class Asm_Jmp
{
char opcode;
DWORD address;

void apply(DWORD jmpAddr)
{
     opcode = 0xE9;
   // calculate realtive addr
   address = jmpAddr;
}


}
#pragma push()

//using it like that
reinterpret_cast<Asm_Jmp*>(addrInstruction)->apply(jmpTarget);

I works nice in my test Application, but i can´t test it in wow atm. so i would like to know if it can work in any target, or may the memory layout different for other targets.
Suggestions about up/downsides of this are welcome.

Thanks in advance