Convert a set of types from or to R supported types
conv_type_ref(x, from = NULL, to = NULL, ignore.case = TRUE)
a character vector of types to be converted. If from is not null, x should be a set of valid types in the from reference. If to is not null, x should be a set of supported R types (SUPPTYPES).
a character vector of length one: the type reference (list_type_ref) of x
a character vector of length one: the targeted type reference (list_type_ref)
should case be ignored when converting `from`` type reference (default: TRUE)
Only from
XOR to
should be set