I built locally with the latest MSVC in c++14 and c++17, but it does not
complain for me. Osman Zakir on llvm-dev reports that they run into
compile errors here.
In any case, it seems prefereable to reuse clang's LLVM.h header to
bring in llvm::Optional and Expected.
#include "PrimType.h"
#include "Program.h"
#include "State.h"
+#include "clang/Basic/LLVM.h"
using namespace clang;
using namespace clang::interp;
-template <typename T> using Expected = llvm::Expected<T>;
-template <typename T> using Optional = llvm::Optional<T>;
-
namespace clang {
namespace interp {