Loyc.Collections.RangeEnumerator< R, T > Struct Template Reference

Helper struct: enumerates through a forward range (IFRange{T}), calling the range methods through R instead of through IFRange{T}. More...

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Source file:

• /Core/Loyc.Essentials/Collections/HelperClasses/RangeEnumerator.cs

Inheritance diagram for Loyc.Collections.RangeEnumerator< R, T >:

Remarks

Helper struct: enumerates through a forward range (IFRange{T}), calling the range methods through R instead of through IFRange{T}.

Although there is a ICloneable{R} constraint on R, it is currently worthless due to a limitation of C#. Since IFRange{T} already includes ICloneable(IFRange(T)), this structure cannot simply invoke Clone() directly because the compiler complains that Clone() is ambiguous. Consequently it is necessary to cast the range to ICloneable{R} just to clone it; if R is a value type then it is boxed, which defeats the entire performance advantage of calling ICloneable{R}.Clone() instead of ICloneable{IFRange{T}}.Clone.

Nevertheless, I have left the constraint in place, in the hope that EC# can eventually eliminate this limitation thanks to its "using" cast. Once EC# compiles directly to CIL, range(using ICloneable<R>).Clone() will not perform boxing.

Type Constraints

R	:	IFRange<T>
R	:	ICloneable<R>

Public fields
R	_range
T	_current

Properties
T	Current [get]
object System.Collections.IEnumerator.	Current [get]

Public Member Functions
	RangeEnumerator (R range)
bool	MoveNext ()
void IDisposable.	Dispose ()
void System.Collections.IEnumerator.	Reset ()