VB6 Unsigned

enum op{
	op_add = 0,
	op_sub = 1,
	op_div = 2,
	op_mul = 3,
	op_mod = 4,
	op_xor = 5,
	op_and = 6,
	op_or  = 7
};

unsigned int __stdcall ULong(unsigned int v1, unsigned int v2, int operation){

	switch(operation){
		case op_add: return v1 + v2;
		case op_sub: return v1 - v2;
		case op_div: return v1 / v2;
		case op_mul: return v1 * v2;
		case op_mod: return v1 % v2;
		case op_xor: return v1 ^ v2;
		case op_and: return v1 & v2;
		case op_or:  return v1 | v2;
	}

	return -1;

}

unsigned short __stdcall UInt(unsigned short v1, unsigned short v2, int operation){

	switch(operation){
		case op_add: return v1 + v2;
		case op_sub: return v1 - v2;
		case op_div: return v1 / v2;
		case op_mul: return v1 * v2;
		case op_mod: return v1 % v2;
		case op_xor: return v1 ^ v2;
		case op_and: return v1 & v2;
		case op_or:  return v1 | v2;
	}

	return -1;

} 

Option Explicit

Enum op
    op_add = 0
    op_sub = 1
    op_div = 2
    op_mul = 3
    op_mod = 4
    op_xor = 5
    op_and = 6
    op_or = 7
End Enum

Private Declare Function ULong Lib "utypes.dll" (ByVal v1 As Long, ByVal v2 As Long, ByVal operation As Long) As Long
Private Declare Function UInt Lib "utypes.dll" (ByVal v1 As Integer, ByVal v2 As Integer, ByVal operation As Long) As Integer

Private Sub Command1_Click()
    On Error Resume Next
    Dim a As Long
    Dim b As Integer
    
    a = 2147483647 + 1
    MsgBox Hex(2147483647) & " + 1 = " & Hex(a) & " Error: " & Err.Description
    Err.Clear
    
    a = -2147483648# - 1
    MsgBox Hex(-2147483648#) & " - 1 = " & Hex(a) & " Error: " & Err.Description
    
    b = 32767 + 1
    MsgBox Hex(32767) & " + 1 = " & Hex(b) & " Error: " & Err.Description
    Err.Clear
    
    b = -32768 - 1
    MsgBox Hex(-32768) & " - 1 = " & Hex(b) & " Error: " & Err.Description

End Sub

Private Sub Form_Load()

    testLong 2147483647, 1, op_add
    testLong -2147483648#, 1, op_sub
    
    testInt 32767, 1, op_add
    testInt -32768, 1, op_sub
    
End Sub




Sub testLong(a As Long, b As Long, opp As op)
    
    Dim ret As Long, o As Variant, msg As String
    o = Array("+", "-", "/", "*", "mod", "xor", "and", "or")
    
    ret = ULong(a, b, opp)
    msg = Hex(a) & " " & o(opp) & " " & Hex(b) & " = " & Hex(ret)
    
    List1.AddItem msg
    Debug.Print msg
End Sub

Sub testInt(a As Integer, b As Integer, opp As op)
    
    Dim ret As Integer, o As Variant, msg As String
    o = Array("+", "-", "/", "*", "mod", "xor", "and", "or")
    
    ret = UInt(a, b, opp)
    msg = Hex(a) & " " & o(opp) & " " & Hex(b) & " = " & Hex(ret)
    
    List1.AddItem msg
    Debug.Print msg
    
End Sub