Imports System.Collections.Generic
Imports System.Runtime.CompilerServices
 
Public Module modDictionaryExtensions
    ''' <summary>Gibt die Liste der Schlüssel zurück, die sich auf einen 
    ' Wert beziehen</summary>
    ''' <param name="Value">Wert, dessen zugeordnete Schlüssel ermittelt 
    ' werden sollen</param>
    <Extension()> _
    Public Function GetKeys(Of T1, T2 As IEquatable(Of T2)) _
       (ByVal dic As Dictionary(Of T1, T2), ByVal Value As T2) As List(Of T1)
        If dic Is Nothing Then Return Nothing
        Return (From kvp As KeyValuePair(Of T1, T2) _
            In dic.Where(Function(kvp As KeyValuePair(Of T1, T2)) _
            Equals(kvp.Value, Value)) _
            Select kvp.Key).ToList
    End Function
End Module