Managed C++/CLI

////////////////////////////////////////////////////////////////////////////
// The System::Collections collection interface implementations

public:
	__property MapTheme* get_Item(int index)
	{
		return __try_cast<MapTheme*>(List->Item[index]);
	}

	__property void set_Item(int index, MapTheme* value)
	{
		List->Item[index] = value;
	}

<br />
public __gc class MyData { /**/ };<br />
<br />
public __gc class MyCollection<br />
: public CollectionBase<br />
{<br />
public:<br />
    __property MyData * get_Item(int in_index)<br />
    {<br />
        return static_cast<MyData*>(List->Item[in_index]);<br />
    }<br />
<br />
    __property void set_Item(int in_index, MyData * in_data)<br />
    {<br />
        List->Item[in_index] = in_data;<br />
    }<br />
};<br />

<br />
Covariant4.cpp(19) : error C3815: Der Rückgabetyp der Methode 'MyCollection::get_Item' muss mit dem Typ des letzten Parameters von 'System::Collections::IList::set_Item' übereinstimmen<br />
        Covariant4.cpp(18) : Siehe Deklaration von 'MyCollection::get_Item'<br />
        Covariant4.cpp(6) : Siehe Deklaration von 'System::Collections::IList::set_Item'<br />
Covariant4.cpp(19) : error C2392: 'MyData __gc *MyCollection::get_Item(int)' : Covariant-Rückgabetypen werden in verwalteten Typen nicht unterstützt<br />

#pragma once


namespace MustGo2
{
	using namespace System;
	using namespace System::ComponentModel;
	using namespace System::Collections;
	using namespace System::Windows::Forms;
	using namespace System::Data;
	using namespace System::Drawing;

	/// <summary> 
	/// Summary for Form1
	///
	/// WARNING: If you change the name of this class, you will need to change the 
	///          'Resource File Name' property for the managed resource compiler tool 
	///          associated with all .resx files this class depends on.  Otherwise,
	///          the designers will not be able to interact properly with localized
	///          resources associated with this form.
	/// </summary>
	public __gc class Form1 : public System::Windows::Forms::Form
	{	
	public:
		Form1(void)
		{
			InitializeComponent();
		}
  
	protected:
		void Dispose(Boolean disposing)
		{
			if (disposing && components)
			{
				components->Dispose();
			}
			__super::Dispose(disposing);
		}
	private: System::Windows::Forms::Form*  panel1;

	private:
		/// <summary>
		/// Required designer variable.
		/// </summary>
		System::ComponentModel::Container * components;

		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		void InitializeComponent(void)
		{
			this->panel1 = new System::Windows::Forms::Form();
			this->panel1->TopLevel = false;
			this->SuspendLayout();
			// 
			// panel1
			// 
			this->panel1->AutoScaleBaseSize = System::Drawing::Size(5, 12);
			this->panel1->ClientSize = System::Drawing::Size(248, 198);
			this->panel1->FormBorderStyle = System::Windows::Forms::FormBorderStyle::Fixed3D;
			this->panel1->Location = System::Drawing::Point(16, 16);
			this->panel1->Name = S"panel1";
			this->panel1->Visible = true;
			// 
			// Form1
			// 
			this->AutoScaleBaseSize = System::Drawing::Size(5, 12);
			this->ClientSize = System::Drawing::Size(292, 266);
			this->Controls->Add(this->panel1);
			this->Name = S"Form1";
			this->Text = S"Form1";
			this->ResumeLayout(false);

		}	
	};
}