Varying length character strings by John Reid

[John Chludzinski]

Should the code contained in:
ftp://ftp.nag.co.uk/sc22wg5/N1901-N1950/N1913.txt be compilable using
the gfortran compiler?

I'm using:

$ gfortran --version
GNU Fortran (GCC) 4.7.2 20120921 (Red Hat 4.7.2-2)

I'm getting:

$ gfortran vs.f95
vs.f95:97.1:

 PURE FUNCTION s_to_c(string) ! generic CHAR
 1
Error: CHARACTER(*) function 's_to_c' at (1) cannot be pure
vs.f95:97.1:

 PURE FUNCTION s_to_c(string) ! generic CHAR
 1
Error: CHARACTER(*) function 's_to_c' at (1) cannot be pure
vs.f95:628.4:

USE ISO_VARYING_STRING
    1
Fatal Error: Can't open module file 'iso_varying_string.mod' for
reading at (1): No such file or directory