Using functional languages to facilitate C++ metaprogramming

Abstract

Template and Preprocessor Metaprogramming are both wellknown in the C++ community to have much in common with Functional Programming (FP). Recently, very few research threads on underpinning these commonalities have emerged to empower cross-development of C++ Metaprogramming (C++MP) and FP. In this paper, we program a self-contained real-world example in a side-by-side fashion to explore the usefulness of a few mainstream FP languages for this purpose: We develop a compile-time abstract datatype for Rational Numbers in C++. We then present the runtime equivalent in HASKELL, F#, and Scala to discuss some FP parallels across the languages. Here, we consider semi-automatic translation between C++MP and FP languages, for earlier studies on these parallels have already obviated the impracticability of fully automatic translations. Our study also shows the superiority of multiparadigm FP languages over single-paradigm ones. In particular, we conclude Scala to currently be the most promising FP language for facilitating C++MP.

Intrinsic Currying for C++ Template Metaprograms

“…Armed with that, they suggest further examination of semi-automatic cross-lingual development between C++ metaprogramming and hybrid functional programming languages. Haeri et al [16] examine that suggestion for Scala and F . Lincke et al [19] discuss a real-world semi-automatic translation from Haskell specifications into efficient C++ metaprograms.…”

“…The Pointfree.io website is an excellent resource for producing such translations 16. A Curtains definition of the Haskell flip combinator is provided in Appendix A.4.…”