public static int Sum <TEnumerator>(this IStrongEnumerable <int, TEnumerator> source)
where TEnumerator : struct, IStrongEnumerator <int>
{
int sum = 0;
foreach (var number in source)
{
sum += number;
}
return(sum);
}
public static bool Any <T, TEnumerator>(this IStrongEnumerable <T, TEnumerator> source, Predicate <T> predicate)
where TEnumerator : struct, IStrongEnumerator <T>
{
var enumerator = source.GetEnumerator();
while (enumerator.MoveNext())
{
if (predicate.Invoke(enumerator.Current))
{
return(true);
}
}
return(false);
}
/// <summary>
/// possible further optimizations: move from the end to the start
/// </summary>
public static T Last <T, TEnumerator>(this IStrongEnumerable <T, TEnumerator> source)
where TEnumerator : struct, IStrongEnumerator <T>
{
var enumerator = source.GetEnumerator();
if (!enumerator.MoveNext())
{
throw new InvalidOperationException();
}
while (enumerator.MoveNext())
{
}
return(enumerator.Current);
}
