Given two classes
class Contract
{
public int ID {get; set;}
// . . .
}
class DBContract
{
public int FromID {get; set;}
// . . .
}
And two IEnumerables
IEnumerable<Contract> ValidContracts = Application.GetContracts(//. . .
IEnumerable<DBContract> ExportedContracts = DBAdapter.GetRows(// . . .
I need to find intersection of theese IEnumerables. But how do I implement IEqualityComparer, if it only has one type argument?
You could implement Intersect yourself, but without using HashSet, something like:
public static IEnumerable<TFirst> Intersect<TFirst, TSecond>(this IEnumerable<TFirst> first, IEnumerable<TSecond> second,
Func<TFirst, TSecond, bool> comparerFunc)
{
return first.Where(firstItem => second.Any(secondItem => comparerFunc(firstItem, secondItem)));
}
And use it like:
IEnumerable<Contract> ValidContracts = Application.GetContracts(//. . .
IEnumerable<DBContract> ExportedContracts = DBAdapter.GetRows(// . . .
var intersect = ValidContracts.Intersect(ExportedContracts, (contract, dbContract) => contract.ID == dbContract.FromID);