Specific Parameter Input - c++

Question

I am fairly new to C++ so forgive me for being all over the place with my code but here is whats going on, I am creating a Dynamic Link Library that will handle the decompression of my games assets. I am very familiar with lossless binary compression but here's whats happening, I need to know how I can have an argument either be "Type A" or "Type B" and nothing else, I am using visual studio so I would like the autocomplete hint to tell me I can either use "A" or "B" as the argument, How would I do this?
cpp
//People where telling me to add code for visual so here
static __declspec(dllexport) char* compress(char* buffer, "8bit Int" | "16bit Int" | "32bit Int", int Value)
{
char* bytes;
//Enter code to convert integer to bytes
strcat_s(bytes, sizeof(bytes) + sizeof(buffer), buffer);
return buffer;
}

Answer 1

Like this?
enum class Integer
{
UNKNOWN = 0,
Bit8 = 1,
Bit16 = 2,
Bit32 = 3,
};
static __declspec(dllexport) char* compress(
char* buffer, Integer intType, int Value)
{
char* bytes;
switch (intType)
{
case Integer::Bit8:
// 8-bits processing.
break;
case Integer::Bit16:
// 16-bits processing.
break;
case Integer::Bit32:
// 32-bits processing.
break;
}
//Enter code to convert integer to bytes
strcat_s(bytes, sizeof(bytes) + sizeof(buffer), buffer);
return buffer;
}
Then you call it this way:
compress(buf, Integer::Bit8, 42);

Answer 2

Does this look appropriate?
__declspec(dllexport) enum intType {
_8bit, _16bit, _32bit
};
class COMPRESS
{
public:
char* CreateBuffer(int Size)
{
char* buffer = new char[Size];
return buffer;
}
char* BufferWrite(char* Buffer, intType Type, int Value)
{
char* bytes;
switch (Type)
{
_8bit:
{
bytes = (char*)Value;
}
_16bit:
{
bytes[0] = Value & 0xff;
bytes[1] = (Value >> 8) & 0xff;
}
_32bit:
{
bytes[0] = Value & 0xff;
bytes[1] = (Value >> 8) & 0xff;
bytes[2] = (Value >> 16) & 0xff;
bytes[3] = (Value >> 24) & 0xff;
}
}
strcat_s(Buffer, sizeof(bytes) + sizeof(Buffer), bytes);
return Buffer;
}