  Dark matter may be in the form of non-baryonic structures such as compact
subhalos and boson stars. Structures weighing between asteroid and solar masses
may be discovered via gravitational microlensing, an astronomical probe that
has in the past helped constrain the population of primordial black holes and
baryonic MACHOs. We investigate the non-trivial effect of the size of and
density distribution within these structures on the microlensing signal, and
constrain their populations using the EROS-2 and OGLE-IV surveys. Structures
larger than a solar radius are generally constrained more weakly than
point-like lenses, but stronger constraints may be obtained for structures with
mass distributions that give rise to caustic crossings or produce larger
magnifications.
