public static TSource[] ToArray <TSource>(this IEnumerable <TSource> source)
{
if (source == null)
{
throw Error.ArgumentNull("source");
}
IIListProvider <TSource> arrayProvider = source as IIListProvider <TSource>;
return(arrayProvider != null?arrayProvider.ToArray() : EnumerableHelpers.ToArray(source));
}
public int GetCount(bool onlyIfCheap)
{
IIListProvider <TElement> listProv = source as IIListProvider <TElement>;
if (listProv != null)
{
return(listProv.GetCount(onlyIfCheap));
}
return(!onlyIfCheap || source is ICollection <TElement> || source is ICollection?source.Count() : -1);
}
public static List <TSource> ToList <TSource>(this IEnumerable <TSource> source)
{
if (source == null)
{
throw Error.ArgumentNull("source");
}
IIListProvider <TSource> listProvider = source as IIListProvider <TSource>;
return(listProvider != null?listProvider.ToList() : new List <TSource>(source));
}
public int GetCount(bool onlyIfCheap)
{
if (onlyIfCheap)
{
return(_source switch
{
IIListProvider <TSource> listProv => listProv.GetCount(onlyIfCheap: true),
ICollection <TSource> colT => colT.Count,
ICollection col => col.Count,
_ => - 1,
});
public override int GetCount(bool onlyIfCheap)
{
IIListProvider <TSource> listProv = _source as IIListProvider <TSource>;
if (listProv != null)
{
int count = listProv.GetCount(onlyIfCheap);
return(count == -1 ? -1 : count + (_appended == null ? 0 : _appended.Count) + (_prepended == null ? 0 : _prepended.Count));
}
return(!onlyIfCheap || _source is ICollection <TSource>?_source.Count() + (_appended == null ? 0 : _appended.Count) + (_prepended == null ? 0 : _prepended.Count) : -1);
}
public int GetCount(bool onlyIfCheap)
{
int count;
if (!onlyIfCheap || _source is ICollection <TSource> || _source is ICollection)
{
count = _source.Count();
}
else
{
IIListProvider <TSource> listProv = _source as IIListProvider <TSource>;
count = listProv == null ? -1 : listProv.GetCount(onlyIfCheap: true);
}
return(count == 0 ? 1 : count);
}
/// <summary>
/// Fully enumerates the provided enumerable and stores its items into an array.
/// </summary>
/// <param name="source">The enumerable to be store.</param>
internal Buffer(IEnumerable <TElement> source)
{
IIListProvider <TElement> iterator = source as IIListProvider <TElement>;
if (iterator != null)
{
TElement[] array = iterator.ToArray();
_items = array;
_count = array.Length;
}
else
{
_items = EnumerableHelpers.ToArray(source, out _count);
}
}
public int GetCount(bool onlyIfCheap)
{
if (onlyIfCheap)
{
IIListProvider <TSource> listProv = _source as IIListProvider <TSource>;
if (listProv != null)
{
return(listProv.GetCount(onlyIfCheap: true));
}
if (!(_source is ICollection <TSource>) && !(_source is ICollection))
{
return(-1);
}
}
return(_source.Count());
}
public static int Count <TSource>(this IEnumerable <TSource> source)
{
if (source == null)
{
throw Error.ArgumentNull(nameof(source));
}
ICollection <TSource> collectionoft = source as ICollection <TSource>;
if (collectionoft != null)
{
return(collectionoft.Count);
}
IIListProvider <TSource> listProv = source as IIListProvider <TSource>;
if (listProv != null)
{
return(listProv.GetCount(onlyIfCheap: false));
}
ICollection collection = source as ICollection;
if (collection != null)
{
return(collection.Count);
}
int count = 0;
using (IEnumerator <TSource> e = source.GetEnumerator())
{
checked
{
while (e.MoveNext())
{
count++;
}
}
}
return(count);
}
public List <IGrouping <TKey, TElement> > ToList()
{
IIListProvider <IGrouping <TKey, TElement> > lookup = Lookup <TKey, TElement> .Create(_source, _keySelector, _elementSelector, _comparer);
return(lookup.ToList());
}
public async Task <List <IAsyncGrouping <TKey, TElement> > > ToListAsync(CancellationToken cancellationToken)
{
IIListProvider <IAsyncGrouping <TKey, TElement> > l = await Internal.Lookup <TKey, TElement> .CreateAsync(source, keySelector, elementSelector, comparer, cancellationToken).ConfigureAwait(false);
return(await l.ToListAsync(cancellationToken).ConfigureAwait(false));
}
