Bitwise flags in Delphi

Question

I need to check if a certain flag is set for an integer.

I already know how to set a flag:

flags := FLAG_A or FLAG_B or FLAG_C

But

Answer 1

I usually use this function:

// Check if the bit at ABitIndex position is 1 (true) or 0 (false)
function IsBitSet(const AValueToCheck, ABitIndex: Integer): Boolean;
begin
  Result := AValueToCheck and (1 shl ABitIndex) <> 0;
end;

and the setters:

// set the bit at ABitIndex position to 1
function SetBit(const AValueToAlter, ABitIndex: Integer): Integer;
begin
  Result := AValueToAlter or (1 shl ABitIndex);
end;

// set the bit at ABitIndex position to 0
function ResetBit(const AValueToAlter, ABitIndex: Integer): Integer;
begin
  Result := AValueToAlter and (not (1 shl ABitIndex));
end;

Note there is no range checking, just for performance. But easy to add if u need to