__gc
Visual Studio .NET 2003
Declares a __gc type.
__gc array-specifier __gc class-specifier __gc struct-specifier __gc interface-specifier __gc pointer-specifier __gc new
Remarks
A __gc type is a C++ language extension that simplifies .NET Framework programming by providing features such as interoperability and garbage collection.
For information and examples on declaring __gc types, see:
- __gc arrays
- __gc classes or __gc structs
- __gc interfaces
- __gc pointers
Note Every member function of an abstract __gc class must be defined unless the member function is pure virtual.
For more information on the rules for __gc types, see 4 __gc Classes.
For more information on creating and using __gc types, see Managed Extensions for C++ Programming.
In Managed Extensions for C++, the equivalents to a C# class and a C# struct are as follows:
| Managed Extensions for C++ | C# | For more information |
|---|---|---|
| __gc struct or __gc class | class | class keyword |
| __value struct or __value class | struct | struct keyword |
Example
In the following example, a managed class (X) is declared with a public data member, which is manipulated through a managed pointer:
// keyword__gc.cpp
// compile with: /clr
#using <mscorlib.dll>
using namespace System;
__gc class X
{
public:
int i;
int ReturnInt() { return 5; }
};
int main()
{
// Because X is a __gc class, this automatically makes px a __gc pointer
X* px;
px = new X; // creates a managed object of type X
Console::WriteLine(px->i);
px->i = 4; // modifies X::i through px
Console::WriteLine(px->i);
int n = px->ReturnInt(); // calls X::ReturnInt through px
Console::WriteLine(n);
return 0;
}
Output
0 4 5
See Also
Managed Extensions for C++ Reference | C++ Keywords | 4 __gc Classes
