Imports System.Runtime.CompilerServices

Module IDictionaryEx
    <Extension()>
    Function GetOrDefault(Of TKey, TValue)(pDictionary As Dictionary(Of TKey, TValue), pKey As TKey, Optional pOnMissing As TValue = Nothing) As TValue
        Dim oValue As TValue

        If pKey Is Nothing Then
            Return Nothing
        End If

        Return IIf(pDictionary.TryGetValue(pKey, oValue), oValue, pOnMissing)
    End Function

    <Extension()>
    Function GetOrInsertNew(Of T, U As New)(dic As Dictionary(Of T, U), key As T) As U
        If dic.ContainsKey(key) Then Return dic(key)
        Dim newObj As U = New U()
        dic(key) = newObj
        Return newObj
    End Function
End Module