Commits
François Saint-Jacques authored and Benjamin Kietzman committed 1accdc93f0d
ARROW-7210: [C++][R] Allow Numeric <-> Temporal Scalar casts The end goal of this PR is to minimally support filtering in R on temporal columns. - Refactor Scalar classes - Follow the same hierarchy as the type hierarchy. - Provide 2 constructor for each Scalar, one for constructing a Null value and one providing an explicit value. The is_valid flag is not required by caller anymore. - All scalar types provide a non failing null constructor, i.e MakeNullScalar will not fail. - Ensure that we can cast from a NumericScalar to a TemporalScalar - Add R unit test Closes #5921 from fsaintjacques/ARROW-7210-scalar-cast-time and squashes the following commits: 648756873 <François Saint-Jacques> Rebase 3db4b9cfe <François Saint-Jacques> Review 4b6965551 <François Saint-Jacques> Try MSCV fix ea1eb9f6f <François Saint-Jacques> ARROW-7210: Allow Numeric <-> Temporal casts Authored-by: François Saint-Jacques <fsaintjacques@gmail.com> Signed-off-by: Benjamin Kietzman <bengilgit@gmail.com>