VipsArgumentFlags

Flags we associate with each object argument.

Have separate input & output flags. Both set is an error; neither set is OK.

Input gobjects are automatically reffed, output gobjects automatically ref us. We also automatically watch for “destroy” and unlink.

VipsArgumentFlags is handy for arguments which are set from C. For example, VipsImage:width is a property that gives access to the Xsize member of struct _VipsImage. We default its ‘assigned’ to TRUE since the field is always set directly by C.

VipsArgumentFlags arguments are not shown in help text, are not looked for if required, are not checked for “have-been-set”. You can deprecate a required argument, but you must obviously add a new required argument if you do.

Input args with VipsArgumentFlags will be modified by the operation. This is used for things like the in-place drawing operations.

VipsArgumentFlags stops the argument being used in hash and equality tests. It’s useful for arguments like revalidate which control the behaviour of the operator cache.