To: J3                                                     J3/18-147
From: Daniel Chen
Subject: Intrinsics to convert C string and Fortran string
Date: 2018-February-15

Discussion
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It is desired to be able to pass a null-terminated string from
Fortran to C or convert a C string to a Fortran string.

Proposal
--------
Need to create two intrinsic functions as:


CSTRING(STRING)
1 Description. Convert a Fortran character string to a
               NULL-terminated C string.
2 Class. Transformational function.
3 Argument. STRING shall be a character scalar.
4 Result Characteristics. Character with the same kind type
         parameter value as STRING and with a length that is the
         length of STRING plus 1 for the NULL terminator.
5 Result Value. The value of the result is the same as STRING except
                a NULL terminator is appended to the end.

FSTRING(STRING)
1 Description. Convert a C string to a Fortran string.
2 Class. Transformational function.
3 Argument. STRING shall be a character scalar.
4 Result Characteristics. Character with the same kind type
         parameter value as STRING and with a length that is the
         length of STRING prior to the first NULL terminator
         if there is one.
5 Result Value. The value of the result is the same as STRING up to
                the first NULL terminator.