since the unit code within opm-parser is now a drop-in replacement,
this simplifies things and make them less error-prone.
unfortunately, this requires quite a few PRs. (most are pretty
trivial, though.)
opm-parser#677 changes the return types for the Deck family of classes.
This patch fixes all broken code from that patch set.
https://github.com/OPM/opm-parser/pull/677
Several files stopped compiling due to relying on opm-parser headers
doing includes. From opm-parser PR-656
https://github.com/OPM/opm-parser/pull/656 this assumption is no longer
valid.
