withUnsafeMutableBufferPointers とかあればいいのかなぁ。 withUnsafeMutableBufferPointers(of: [a, b]) { pointers in for i in 0..<count { pointers[0][i] += pointers[1][i] } } (edited)withUnsafeMutableBufferPointers とかあればいいのかなぁ。 withUnsafeMutableBufferPointers(of: [a, b]) { pointers in for i in 0..<count { pointers[0][i] += pointers[1][i] } } (edited)Mutable が抜けたBuffer もいるかな。& じゃないとダメか。