C++ :: Algorithm For Deleting Lines In Tetris?

I'm making tetris but didn't go the conventional way of using matrices to hold binary id's of my shapes. I thought it would be easier that way, but now I'm stuck on deleting complete lines of blocks. Here is my code that checks for complete lines:

bool lineComplete = true;
std::vector<sf::FloatRect> lineTest;
sf::RectangleShape rect;
rect.setSize(sf::Vector2f(1, 1));

[Code] .....

Now in RemoveLine(), I need to access the individual blocks of each gamePiece. Each gamePiece has a vector of sf::RectangleShapes (SFML), which represent one block of that tetromino:

std::vector<sf::RectangleShape> pieceRectangles_; the sf::RectangleShapes are stored like so:
case 0:
//line
for(int i = 0; i < 4; i++){
sf::RectangleShape rect(sf::Vector2f(10, 10));
rect.setPosition(origin.position.x + (i * 10), origin.position.y);
rect.setTexture(&imgr.tetrominoTexture);
rect.setFillColor(sf::Color(243, 16, 16));
pieceRectangles_.push_back(rect);
}

My question is how do I got about accessing particular sf::RectangleShapes stored in this vector if that sf::RectangleShape is located on a complete line that is being deleted? Would I need to create a Block class and give it members that hold each block's location?