I would like to convert unsigned int to uint64 inside C function. uint64 is defined in R package int64.
EDIT
This question is about conversion from C unsigned int data type to uint64 R language data type.
"int64 package has been developped so that 64 bit integer vectors are represented using only R data structures, i.e data is not represented as external pointers to some C++ object. Instead, each 64 bit integer is represented as a couple of regular 32 bit integers, each of them carrying half the bits of the underlying 64 bit integer. This was a choice by design so that 64 bit integer vectors can be serialized and used as data frame columns."