On the role of language constructs for framework design

The relationship between framework design and
language constructs are discussed for two reasons:
firstly, designing frameworks requires the ability to
give the framework designer precise control over
aspects of the framework extensions; secondly, the
framework constraints should be specified such that
they are statically checkable. Four existing language
constructs are discussed: generalized block structure,
generalized inheritance, generalized virtuality, and
singular objects. It is discussed how these language
constructs give precise means for controlling the
framework extensions in statically checkable ways.