public static void OutOfRange(int paramValue, int maxValue, /*[CallerArgumentExpression("paramValue")]*/ string paramName)
{
if ((uint)paramValue >= (uint)maxValue)
{
Throw.ArgumentOutOfRangeException(paramName);
}
}
static TSource ElementAt <TList, TSource>(this TList source, int index, int skipCount, int takeCount)
where TList : notnull, IReadOnlyList <TSource>
{
var item = TryElementAt <TList, TSource>(source, index, skipCount, takeCount);
return(item.HasValue
? item.Value
: Throw.ArgumentOutOfRangeException <TSource>(nameof(index)));
}
public static RepeatEnumerable <TSource> Repeat <TSource>(TSource value, int count)
{
if (count < 0)
{
Throw.ArgumentOutOfRangeException(nameof(count));
}
return(new RepeatEnumerable <TSource>(value, count));
}
public readonly TSource this[int index]
{
get
{
if (index < 0 || index >= Count)
{
Throw.ArgumentOutOfRangeException(nameof(index));
}
return(source[index + skipCount]);
}
}
public static RangeEnumerable Range(int start, int count)
{
if (count < 0)
{
Throw.ArgumentOutOfRangeException(nameof(count));
}
try
{
_ = checked (start + count);
}
catch (OverflowException)
{
Throw.ArgumentOutOfRangeException(nameof(count));
}
return(new RangeEnumerable(start, count));
}
public static TSource ElementAt <TEnumerable, TEnumerator, TSource>(this TEnumerable source, int index)
where TEnumerable : notnull, IValueReadOnlyCollection <TSource, TEnumerator>
where TEnumerator : struct, IEnumerator <TSource>
{
if (index >= 0 && index < source.Count)
{
using var enumerator = source.GetEnumerator();
for (; enumerator.MoveNext(); index--)
{
if (index == 0)
{
return(enumerator.Current);
}
}
}
return(Throw.ArgumentOutOfRangeException <TSource>(nameof(index)));
}
public static async ValueTask <TSource> ElementAtAsync <TEnumerable, TEnumerator, TSource>(this TEnumerable source, int index, CancellationToken cancellationToken = default)
where TEnumerable : notnull, IAsyncValueEnumerable <TSource, TEnumerator>
where TEnumerator : struct, IAsyncEnumerator <TSource>
{
if (index >= 0)
{
var enumerator = source.GetAsyncEnumerator(cancellationToken);
await using (enumerator.ConfigureAwait(false))
{
for (; await enumerator.MoveNextAsync().ConfigureAwait(false); index--)
{
if (index == 0)
{
return(enumerator.Current);
}
}
}
}
return(Throw.ArgumentOutOfRangeException <TSource>(nameof(index)));
}
public TSource this[int index] => Throw.ArgumentOutOfRangeException <TSource>(nameof(index));