[Boost-users] How should I define a wchar_t type for use in mbtowc? [Android] [Serialization]

I'm attempting to port Serialization code to Android. Android-ndk-r8d does not have mbtowc implemented, which Serialization apparently uses, somewhere. I would like to recreate this function myself, rather than find another Serialization library entirely or write one myself. The function leverages the wchar_t type, which also does not appear to built into android-ndk-r8d. What is boost serialization expecting this type to be? Can I grab an implementation of it from off of a shelf somewhere?