`join_rows()` and `join_cols()`
This is built on top of the prototype in !23 (closed).
Just like every other prediction of the work necessary in #20 (closed) was wrong, this support (which was listed as "may need custom kernels") indeed did not need any custom kernels above and beyond what was already implemented. Anyway, that's not a bad thing.
The MR implements join_rows()
and join_cols()
for up to four arguments, just like Armadillo. glue_join_rows
and glue_join_cols
are used for delayed evaluation for the two-argument versions, but three- and four-argument versions evaluate directly. conv_to
s inside of expressions are wrapped into the joining operation for extra efficiency.