   the integer 102 and the remaining 16 bits are specified on
   the rest. On the last example, we expect a rest with size 32,
   which won't match.
+
+  Size and unit are not applicable to utf8, utf16, and utf32.
+
+  The default size for integers is 8. For floats, it is 64. For
+  binaries, it is the size of the binary. Only the last binary
+  in a binary match can use the default size (all others must
+  have their size specified explicitly). Bitstrings do not have
+  a default size.
+
+  The default unit for integers, floats, and bitstrings is 1. For
+  binaries, it is 8.
+
+  For floats, unit * size must result in 32 or 64, corresponding
+  to binary32 and binary64, respectively.
   """
   defmacro :<<>>.(args)
 

  ## Bitstring types

  A bitstring may contain many parts and those may have
  specifi types. Most of the time, Elixir will figure out
  the part's type and won't require any work from you:

      <<102, "oo">>


  """
  defmacro __aliases__(args)
end
