binding -- a g:binding object
from -- a g:value instance in which to store the value to transform
to -- a g:value instance in which to store the transformed value
result -- True if the transformation was successful, and false otherwise.

The callback function for the g:object-bind-property-full function to be called to transform from to to. If this is the transform-to function of a binding, then from is the source property on the source object, and to is the target property on the target object. If this is the transform-from function of a :bidirectional binding, then those roles are reversed.