             throw GraphError.VertexNotPresent
         }
 
-        var result: [Vertex] = []
+        var result = [Vertex]()
 
         for row in 0..<index {
             if matrix[row, index] == 1 {

        if col >= nCols {
            return Bit.Zero
        }
        var newContents: [T] = []
        for (index, item) in contents.enumerate() {
            if (index % nCols) != 0 {
                newContents.append(item)

    */
    public var edges: [(Vertex, Vertex)] {
        get {
            var result = [(Vertex, Vertex)]()
            for row in 0..<size {
                for col in row..<size {
                    if matrix[row, col] == 1{
