Splatting: tuple deconstruction for argument list

TupleSplatting.cs

(int sum, int count) Tally(IEnumerable<int> values)
{
    sum = 0; count = 0;
    foreach (var value in values) { sum += value; count++; }
}

double Average(int sum, int count) => count == 0 ? 0 : sum / count;

var avg = Average(Tally(new[] { 1, 2, 3, 4, 5})); // タプル (int sum, int count) を分解して、Averabe(sum, count) に渡す