While compiling my code with checking against the Fortran 2008 standard turned on. The compiler outputs
warning #7410: Fortran 2008 does not allow this keyword. [CONVERT]
The code in question uses the convert argument of "open" to allow open_append, open_new, and open_read to switch type during a run.
OPEN( unit = UNITNUMBER, file = FILENAME, form = FORMATTYPE, convert = CONVERT_ENDIANNESS, &
status = 'old', iostat = errflag, action = 'READWRITE' )
Where CONVERT_ENDIANNESS can be set to "native", "little_endian", "big_endian".
Convert has worked fine for a long time. What is the proper way to get the some functionality in Fortran 2008?
CONVERT= in OPEN was a DEC extension inherited by the Intel compiler. There is no similar feature in standard Fortran. It still works, but will get you standards warnings if you ask for them (which you did - it's not default). (There are additional values for CONVERT=, by the way...)