Conversions between Coproducts and Eithers

[mgzuber]

Closes #648

[codecov-io]

Codecov Report

Merging #699 into master will increase coverage by 0.06%.
The diff coverage is 93.75%.

@@            Coverage Diff             @@
##           master     #699      +/-   ##
==========================================
+ Coverage   83.52%   83.58%   +0.06%     
==========================================
  Files          65       66       +1     
  Lines        2592     2608      +16     
  Branches       93       90       -3     
==========================================
+ Hits         2165     2180      +15     
- Misses        427      428       +1

Impacted Files	Coverage Δ
...re/src/main/scala/shapeless/syntax/coproduct.scala	97.87% <100%> (+0.04%)	✅
...e/src/main/scala/shapeless/syntax/std/either.scala	100% <100%> (ø)
core/src/main/scala/shapeless/ops/coproduct.scala	83.88% <92.3%> (+0.47%)	✅

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a196f79...cb49112. Read the comment docs.

[milessabin]

This is great stuff ... many thanks!

Would you consider doing the equivalent for nested pairs as well?

Anyhow ... merging :-)

[mgzuber]

@milessabin you mean something along the lines of:

val t = (1, ("abc", (false, 2.0)))
val h = t.toHList
typed[Int :: String :: Boolean :: Double :: HNil](h)

?

[milessabin]

Exactly so.