;+
; NAME:
;  indexcount
; PURPOSE: (one line)
;  return the count in an index array, or 0 for -1
; DESCRIPTION:
;  return the count in an index array, or 0 for -1
; CATEGORY:
;  Utility
; CALLING SEQUENCE:
;  count = indexcount(index)
; INPUTS:
;  index = as returned by where, an array of longs, or -1
; OUTPUTS:
;  0 if index = -1, n_elements(index) otherwise
; PROCEDURE
; MODIFICATION HISTORY:
;  Written 2011 Aug 24, by Leslie Young, SwRI
;-

function indexcount, index

    n_dim_val = size(index, /n_dim)

    ; not a scalar, return length of array
    if n_dim_val gt 0 then return, n_elements(index)

    if long(index) eq -1L then return, 0L else return, 1L

end