[c++11 - win32] - combination keys for do some actions

[joaquim]

i have the function for test 1 key\combination keys(using a vector) if they are pressed:

//test if a key\combination keys is pressed
bool AreAllKeysPressed(const std::vector<int> &keys)
{
    int state = 0x8000;
    for (int key:keys)//please anyone can explain to me these type of 'for' ?
    {
        state &= GetAsyncKeyState(key);
    }

    return (state & 0x8000) != 0;
}

maybe i have 1 problem in these function and i don't know.
these function go thro the vector and test if the keys are pressed in same time(1 or more keys that can be in vector).
and heres the function that do more combination:

bool CombineKeys(std::vector<std::vector<int>> const &keys)
{
    static bool PreviousKeyPressed=false;
    static DWORD StartTimer = GetTickCount();
    static int i;

        //test if the 1st key\combination key is pressed
        if((AreAllKeysPressed(keys[0])==true) && PreviousKeyPressed==false)
        {
            i=0;
            PreviousKeyPressed=true;
            StartTimer = GetTickCount();
            i++;
        }
        //the user only have 2 seconds for press the next key\combination key
        else if (GetTickCount() - StartTimer >= 2000)//now i put the timer here ;)
        {
            StartTimer =GetTickCount();
            PreviousKeyPressed=false;
            i=0;
        }
        //test if the previous key\combination keys was pressed
        //and the last key\combination keys
        else if((i==(int)keys.size()-1) && (AreAllKeysPressed(keys[(int)keys.size()-1])==true) && PreviousKeyPressed==true)
        {
            PreviousKeyPressed=false;
            i=0;
            StartTimer=0;
            return true;

        }
        //test if the previous key\combination keys was pressed
        //and the next key\combination keys
        else if((AreAllKeysPressed(keys[i])==true) && PreviousKeyPressed==true)
        {
            PreviousKeyPressed=true;
            StartTimer = GetTickCount();
            i++;
        }

        else
        {
            PreviousKeyPressed=false;
            StartTimer = GetTickCount();
            i=0;
        }

    return false;
}

these function test the combination of keys. the vector is a 2D vector. and test the 1st dimension with the AreAllKeysPressed() function.
and now see these sample(used with keydown message):

if(CombineKeys({{'A', 'S', 'D'}, {'P'}, {'A'}, {'B'}}))
        {
            MessageBox(NULL,"hi","hi",MB_OK);
        }

these sample works fine... but i do:

if(CombineKeys({{'A', 'S', 'D'}, {'P','O'}, {'A'}, {'B'}}))
        {
            MessageBox(NULL,"hi","hi",MB_OK);
        }

don't works... only the 1st combination

'{'A', 'S', 'D'}'

is tested correctly.. but not the 2nd

'{'P','O'}'

why these happens?
because i use a irregular vector? (the 1st index have 3, the 2nd index have 2 and the 3rd and 4th have just 1)
what you can say?

[joaquim]

now i understand why the 1st combination works fine and the don't.
the 1st is more easy to test.. so no problem.. but the others are more dificulty, but how the user can press 2 keys in same and not lose the last combination(it's keydown message and if we don't press that 2 keys in same time, we lose what we did before).
i need some advices for fix these problem.. if anyone, can advice me, please tell me.