Handle wide-strings similarly to how normal strings are already handled.
For now support for them is only available in the ODBC backend.
Also add conversion functions between UTF-{8,16,32} and wchar_t and the
tests for them. Note that some of these functions are not used yet, but
provide the complete set as they probably will be in the future.
Co-Authored-By: Vadim Zeitlin <vz-soci@zeitlins.org>
This is unnecessary as it can be recovered from db_type: even if this is
not lossless, we don't really care about it if all we need is data_type,
so simplify the API and the implementation by only having one "type"
parameter instead of two.
No real changes.
Types that refered to non-fixed-size types have been replaced in favor
of their fixed-size types (e.g. dt_integer -> dt_int32, x_short ->
x_int16). To be backwards compatible, we need to keep all of the
previous types though.
Benjamin Oldenburg