Interface optional_default

takes as arguments a default value and an optional argument, and returns the optional argument value if it's present, otherwise the default value

def -- intent(in), scalar or dimension(:),

logical or integer or real(dp) or complex(dp) or character(len=*)

opt_val -- intent(in), optional, scalar or dimension(size(def)),

logical or integer or real(dp) or complex(dp) or character(len=*)

Return values:

o1 -- logical

o2 -- integer

o3 -- integer, dimension(size(def))

o4 -- real(dp)

o5 -- real(dp), dimension(size(def))

o6 -- complex(dp)

o7 -- character(1024)

inoutput_close subroutine