4.1 Fortran 2003 status

GNU Fortran supports several Fortran 2003 features; an incomplete list can be found below. See also the wiki page about Fortran 2003.

• Intrinsics command_argument_count, get_command, get_command_argument, get_environment_variable, and move_alloc.
• Array constructors using square brackets. That is, [...] rather than (/.../). Type-specification for array constructors like (/ some-type :: ... /).
• FLUSH statement.
• IOMSG= specifier for I/O statements.
• Support for the declaration of enumeration constants via the ENUM and ENUMERATOR statements. Interoperability with gcc is guaranteed also for the case where the -fshort-enums command line option is given.
• TR 15581:
  • ALLOCATABLE dummy arguments.
  • ALLOCATABLE function results
  • ALLOCATABLE components of derived types
• The ERRMSG= tag is now supported in ALLOCATE and DEALLOCATE statements. The SOURCE= tag is supported in an ALLOCATE statement. An intrinsic-type-spec can be used as the type-spec in an ALLOCATE statement; while the use of a derived-type-name is currently unsupported.
• The OPEN statement supports the ACCESS='STREAM' specifier, allowing I/O without any record structure.
• Namelist input/output for internal files.
• The PROTECTED statement and attribute.
• The VALUE statement and attribute.
• The VOLATILE statement and attribute.
• The IMPORT statement, allowing to import host-associated derived types.
• USE statement with INTRINSIC and NON_INTRINSIC attribute; supported intrinsic modules: ISO_FORTRAN_ENV, OMP_LIB and OMP_LIB_KINDS.
• Renaming of operators in the USE statement.
• Interoperability with C (ISO C Bindings)
• BOZ as argument of INT, REAL, DBLE and CMPLX.
• Type-bound procedures with PROCEDURE or GENERIC, and operators bound to a derived-type.
• Extension of derived-types (the EXTENDS(...) syntax).
• ABSTRACT derived-types and declaring procedure bindings DEFERRED.