While OO has become ubiquitously employed for design, implementation, and even conceptualization, many practitioners recognize the concomitant need for other programming paradigms according to problem domain. Nevertheless, the choice of a programming paradigm is strongly influenced by the supporting programming language facilities. In turn, choice of programming language is usually a practical matter; one cannot generally afford to use a language not in the mainstream. We seek answers to the question of how to address the need for other programming paradigms in the general context of OO languages.
Can OO programming languages effectively support other programming paradigms? The tentative answer seems to be affirmative, at least for some paradigms; for example, significant progress has been made for the case of (higher order, polymorphic) functional programming in C++. We show that there are many such efforts extant, including theoretical treatments, language implementations, and practical (application) implementations.