2017-02-27 13:19 GMT+01:00 Kosyrev Serge <skosyrev@ptsecurity.com>:

Good day!

If there is an interest in prior art, /and/ there is a motivation in
making things future-proof, there is that somewhat elaborate construction
coming from Common Lisp:

https://www.cs.cmu.edu/Groups/AI/html/cltl/clm/node203.html
[...]

And something more (= a quarter century ;-) recent from C++-land:

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3505.html

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0011r0.html

Cheers,