OSDev.org

Firestryke31 wrote:A preliminary screenshot of the latest iteration of my OS, "Socks."

SocksPrelim.png

I've got physical/virtual memory management, a simple initial display driver, and have just implemented ISR support. Next I have to implement the system call interface so I can get the IPC system running so I can get the driver interface set up.

The initial display driver, simple kernel heap, and physical memory manager are all C++ classes. The display driver even uses << for text and integers.

Firestryke31 wrote:Yeah, when I first set it up I was amazed at how easy it was to do. Just overload the global functions class& operator<<(class& in, const char* str) for strings and class& operator<<(class& in, const unsigned int) for integers. In my setup these then call class functions to do the actual display, but some just have them as "friend" and make them do the real work. Finally, just return in and you're done.

Creature wrote:Same here, the only thing I ran into was the ambiguity for chars and integers. I ended up using a small 'hack' that prints a character when you use character formatting (e.g. 'c') and always prints an integer when you enter a number (even if that number could be a character).

myOutputClass << myOutputClass::Hex << 'a';            // displays '0x61'
myOutputClass << myOutputClass::Decimal << 'a';      // displays '97'
myOutputClass << myOutputClass::Character << 'a';   // displays 'a'.

This way, once the class receives the character, it automatically reverts to hex and so you don't have to explicitly send the state enumeration prior to every character write.

outputClass << outputClass::Hex << 0xdeadbeef; // "0xdeadbeef"
outputClass << 0xf00d; // also "0xf00d"
outputClass << outputClass::Dec << 1234; // "1234"

pcmattman wrote:Alternatively, have the class keep track of the last state enumeration used:

outputClass << outputClass::Hex << 0xdeadbeef; // "0xdeadbeef"

myIntialisationFunction();  // may or may not use outputClass (I know - global objects == bad :o) )

if(something)
{
  outputClass << 0x1234;
}
else
{
  outputClass << outputClass::Dec << 5678;
}

outputClass << 0xf00d; // also "0xf00d" - or is it?
outputClass << outputClass::Dec << 1234; // "1234"

AJ wrote:Hi,

Creature wrote:Same here, the only thing I ran into was the ambiguity for chars and integers. I ended up using a small 'hack' that prints a character when you use character formatting (e.g. 'c') and always prints an integer when you enter a number (even if that number could be a character).

Another way to deal with this is by inserting an enumeration in to the stream. For example:

Code: Select all

myOutputClass << myOutputClass::Hex << 'a';            // displays '0x61'
myOutputClass << myOutputClass::Decimal << 'a';      // displays '97'
myOutputClass << myOutputClass::Character << 'a';   // displays 'a'.

So the enumeration acts as a type modifier for formatting the output. If you do this, I would suggest that you create the output class with a default output type - for example hexadecimal. This way, once the class receives the character, it automatically reverts to hex and so you don't have to explicitly send the state enumeration prior to every character write.

Cheers,
Adam

Solar wrote:You can't really define this any different than the ios_base modifiers from the C++ standard library do, because otherwise you would have two ways to do output that look identical but aren't really (Bad Thing (tm)).