source: branch/egtra-stream-without-en_dec/Classes/ActiveBasic/misc.ab@ 673

'Classes/ActiveBasic/misc.ab

Namespace ActiveBasic
    Namespace Detail
        /*!
        @brief baseがderivedの基底クラスかどうか判定する。
        @param[in] base 基底クラス
        @param[in] derived 派生クラス
        @retval True baseがderivedの基底クラスである
        @retval False 基底クラスでない
        @exception ArgumentNullException 引数のどちらか又は双方がNoghing
        @auther Egtra
        @date 2008/01/21
        */
        Function IsBaseOf(base As System.TypeInfo, derived As System.TypeInfo) As Boolean
            Imports System
            If IsNothing(base) Then
                Throw New ArgumentNullException("base")
            ElseIf IsNothing(derived) Then
                Throw New ArgumentNullException("derived")
            End If
            Do
                IsBaseOf = derived.Equals(base)
                If IsBaseOf Then
                    Exit Function
                End If
                derived = derived.BaseType
            Loop Until IsNothing(derived)
        End Function
    End Namespace

    Function IsNothing(o As Object) As Boolean
        Return Object.ReferenceEquals(o, Nothing)
    End Function
End Namespace