Compiler Warning (level 3) C4580

[attribute] is deprecated; instead specify System::Attribute as a base class

attribute is no longer the preferred syntax for creating user-defined attributes. For more information, see User-Defined Attributes (C++ Component Extensions).

Example

The following sample generates C3454.

// C4580.cpp
// compile with: /W3 /c /clr
[attribute]   // C4580
public ref class Attr {
public:
   int m_t;
};

public ref class Attr2 : System::Attribute {
public:
   int m_t;
};