You may create a struct with "x" elements, one for each LED:
struct ArrayOfBooleans {
bool array[4];
};
ArrayOfBooleans myOutputArray;
myOutputArray.array[0] = true;
myOutputArray.array[1] = true;
myOutputArray.array[2] = false;
myOutputArray.array[3] = true;
lightEmUp(myOutputArray);
void lightEmUp(ArrayOfBooleans myOutputArray) {
bool isFirstLightOn = myOutputArray.array[0];
// etc
}
NoTE: If you run into Exception 9 issues (using this logic on another board), please check this answer to another post