Example 22.1.  How to use the SFXBrewPointer class

Void SFXPointerExplainer::_SFXBrewPointer(Void) const
{
    // Both of the following variable declarations are equivalent.
    // In general, use the Smp version which is easy to describe.

    SFXBrewPointer<SFBDisplay> display1;
    SFBDisplaySmp display2;

    // To create an instance of the wrapper class, 
    // use the  NewInstance() or GetInstance() function of each wrapper class.
    // It is unnecessary to release the instance since the smart pointer manages it.

    SFBGraphicsSmp graphics;
    SFBGraphicsPtr raw_graphics;

    if ((graphics = SFBGraphics::NewInstance()) != null) {

        // when succeed to create an insatnce
    }

    // Get the raw pointer managed by the smart pointer.

    raw_graphics = graphics.Get();

    // Compare smart pointers of the same type.

    if (display1 == display2) {
    }

    if (display1 != display2) {
    }

    // Compare a smart pointer with a raw pointer.

    if (graphics == raw_graphics) {
    }

    // Compare a smart pointer with a null pointer.

    if (graphics != null) {
    }

    // Compare smart pointers of the different type
    // This is not recommendable, but possible by its desgin.

    if (graphics != display1) {
    }

    // To cast the pointer of an instance managed by the smart pointer, 
    // use the opeartor such as static_pointer_cast.
    // The static_cast opeartor must not be used.

    SFBBaseSmp base;
    SFBBitmapSmp bitmap;

    base = bitmap;
    bitmap = static_pointer_cast<SFBBitmap>(base);

    // Get the empty instance.
    // This can be used as the return value of the reference to the empty instance.

    SFBFileSmpConstRef file(SFBFileSmp::EmptyInstance());

    unused(file);

    // Release the instance managed by the smart pointer explicitly.

    SFBFileMgrSmp filemgr;

    if ((filemgr = SFBFileMgr::NewInstance()) != null) {

        // Call the Release() function of the SFXBrewPointer class.

        filemgr.Release();

        // In the SophiaFramework 3.0 or higher, the AddRef() or Release() function of the SFBBase (IBase) class cannot be called.

        /*
        filemgr->Release();
        */
    }

    return;
}