import std.algorithm, std.container, std.stdio;

​

struct DataPoint {

    immutable ulong time;

    ulong value;

}

​

void main() {

    auto dataPoints = DList!DataPoint([

        DataPoint(10_000_000, 1),

        DataPoint(30_000_000, 3),

        DataPoint(40_000_000, 4),

    ]);

    auto time = 30_000_000;

    auto r = findSplit!((a, b) => a.time == b)(dataPoints[], [time]);

    r[0].front.writeln;

    r[1].front.writeln;

    r[2].front.writeln;

    auto dp = dataPoints[].find(r[1].front);

    writeln("before: ", dataPoints[]);

    dataPoints.insertBefore(dp, DataPoint(20_000_000, 2));

    writeln("after: ", dataPoints[]);

}

​