<html lang="en">
<head>
<title>Fortran 2003 status - The GNU Fortran Compiler</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="The GNU Fortran Compiler">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Fortran-2003-and-2008-status.html#Fortran-2003-and-2008-status" title="Fortran 2003 and 2008 status">
<link rel="next" href="Fortran-2008-status.html#Fortran-2008-status" title="Fortran 2008 status">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being ``Funding Free Software'', the Front-Cover
Texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below). A copy of the license is included in the section entitled
``GNU Free Documentation License''.
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development.-->
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
pre.display { font-family:inherit }
pre.format { font-family:inherit }
pre.smalldisplay { font-family:inherit; font-size:smaller }
pre.smallformat { font-family:inherit; font-size:smaller }
pre.smallexample { font-size:smaller }
pre.smalllisp { font-size:smaller }
span.sc { font-variant:small-caps }
span.roman { font-family:serif; font-weight:normal; }
span.sansserif { font-family:sans-serif; font-weight:normal; }
--></style>
</head>
<body>
<div class="node">
<a name="Fortran-2003-status"></a>
<p>
Next: <a rel="next" accesskey="n" href="Fortran-2008-status.html#Fortran-2008-status">Fortran 2008 status</a>,
Up: <a rel="up" accesskey="u" href="Fortran-2003-and-2008-status.html#Fortran-2003-and-2008-status">Fortran 2003 and 2008 status</a>
<hr>
</div>
<h3 class="section">4.1 Fortran 2003 status</h3>
<p>GNU Fortran supports several Fortran 2003 features; an incomplete
list can be found below. See also the
<a href="http://gcc.gnu.org/wiki/Fortran2003">wiki page</a> about Fortran 2003.
<ul>
<li>Procedure pointers including procedure-pointer components with
<code>PASS</code> attribute.
<li>Procedures which are bound to a derived type (type-bound procedures)
including <code>PASS</code>, <code>PROCEDURE</code> and <code>GENERIC</code>, and
operators bound to a type.
<li>Abstract interfaces and and type extension with the possibility to
override type-bound procedures or to have deferred binding.
<li>Polymorphic entities (“<code>CLASS</code>”) for derived types – including
<code>SAME_TYPE_AS</code>, <code>EXTENDS_TYPE_OF</code> and <code>SELECT TYPE</code>.
Note that the support for array-valued polymorphic entities is incomplete
and unlimited polymophism is currently not supported.
<li>The <code>ASSOCIATE</code> construct.
<li>Interoperability with C including enumerations,
<li>In structure constructors the components with default values may be
omitted.
<li>Extensions to the <code>ALLOCATE</code> statement, allowing for a
type-specification with type parameter and for allocation and initialization
from a <code>SOURCE=</code> expression; <code>ALLOCATE</code> and <code>DEALLOCATE</code>
optionally return an error message string via <code>ERRMSG=</code>.
<li>Reallocation on assignment: If an intrinsic assignment is
used, an allocatable variable on the left-hand side is automatically allocated
(if unallocated) or reallocated (if the shape is different). Currently, scalar
deferred character length left-hand sides are correctly handled but arrays
are not yet fully implemented.
<li>Transferring of allocations via <code>MOVE_ALLOC</code>.
<li>The <code>PRIVATE</code> and <code>PUBLIC</code> attributes may be given individually
to derived-type components.
<li>In pointer assignments, the lower bound may be specified and
the remapping of elements is supported.
<li>For pointers an <code>INTENT</code> may be specified which affect the
association status not the value of the pointer target.
<li>Intrinsics <code>command_argument_count</code>, <code>get_command</code>,
<code>get_command_argument</code>, and <code>get_environment_variable</code>.
<li>Support for unicode characters (ISO 10646) and UTF-8, including
the <code>SELECTED_CHAR_KIND</code> and <code>NEW_LINE</code> intrinsic functions.
<li>Support for binary, octal and hexadecimal (BOZ) constants in the
intrinsic functions <code>INT</code>, <code>REAL</code>, <code>CMPLX</code> and <code>DBLE</code>.
<li>Support for namelist variables with allocatable and pointer
attribute and nonconstant length type parameter.
<li><a name="index-array_002c-constructors-274"></a><a name="index-g_t_0040code_007b_005b_002e_002e_002e_005d_007d-275"></a>Array constructors using square brackets. That is, <code>[...]</code> rather
than <code>(/.../)</code>. Type-specification for array constructors like
<code>(/ some-type :: ... /)</code>.
<li>Extensions to the specification and initialization expressions,
including the support for intrinsics with real and complex arguments.
<li>Support for the asynchronous input/output syntax; however, the
data transfer is currently always synchronously performed.
<li><a name="index-g_t_0040code_007bFLUSH_007d-statement-276"></a><a name="index-statement_002c-_0040code_007bFLUSH_007d-277"></a><code>FLUSH</code> statement.
<li><a name="index-g_t_0040code_007bIOMSG_003d_007d-specifier-278"></a><code>IOMSG=</code> specifier for I/O statements.
<li><a name="index-g_t_0040code_007bENUM_007d-statement-279"></a><a name="index-g_t_0040code_007bENUMERATOR_007d-statement-280"></a><a name="index-statement_002c-_0040code_007bENUM_007d-281"></a><a name="index-statement_002c-_0040code_007bENUMERATOR_007d-282"></a><a name="index-g_t_0040code_007bfshort_002denums_007d-283"></a>Support for the declaration of enumeration constants via the
<code>ENUM</code> and <code>ENUMERATOR</code> statements. Interoperability with
<samp><span class="command">gcc</span></samp> is guaranteed also for the case where the
<samp><span class="command">-fshort-enums</span></samp> command line option is given.
<li><a name="index-TR-15581-284"></a>TR 15581:
<ul>
<li><a name="index-g_t_0040code_007bALLOCATABLE_007d-dummy-arguments-285"></a><code>ALLOCATABLE</code> dummy arguments.
<li><a name="index-g_t_0040code_007bALLOCATABLE_007d-function-results-286"></a><code>ALLOCATABLE</code> function results
<li><a name="index-g_t_0040code_007bALLOCATABLE_007d-components-of-derived-types-287"></a><code>ALLOCATABLE</code> components of derived types
</ul>
<li><a name="index-g_t_0040code_007bSTREAM_007d-I_002fO-288"></a><a name="index-g_t_0040code_007bACCESS_003d_0027STREAM_0027_007d-I_002fO-289"></a>The <code>OPEN</code> statement supports the <code>ACCESS='STREAM'</code> specifier,
allowing I/O without any record structure.
<li>Namelist input/output for internal files.
<li>Further I/O extensions: Rounding during formatted output, using of
a decimal comma instead of a decimal point, setting whether a plus sign
should appear for positive numbers.
<li><a name="index-g_t_0040code_007bPROTECTED_007d-statement-290"></a><a name="index-statement_002c-_0040code_007bPROTECTED_007d-291"></a>The <code>PROTECTED</code> statement and attribute.
<li><a name="index-g_t_0040code_007bVALUE_007d-statement-292"></a><a name="index-statement_002c-_0040code_007bVALUE_007d-293"></a>The <code>VALUE</code> statement and attribute.
<li><a name="index-g_t_0040code_007bVOLATILE_007d-statement-294"></a><a name="index-statement_002c-_0040code_007bVOLATILE_007d-295"></a>The <code>VOLATILE</code> statement and attribute.
<li><a name="index-g_t_0040code_007bIMPORT_007d-statement-296"></a><a name="index-statement_002c-_0040code_007bIMPORT_007d-297"></a>The <code>IMPORT</code> statement, allowing to import
host-associated derived types.
<li>The intrinsic modules <code>ISO_FORTRAN_ENVIRONMENT</code> is supported,
which contains parameters of the I/O units, storage sizes. Additionally,
procedures for C interoperability are available in the <code>ISO_C_BINDING</code>
module.
<li><a name="index-g_t_0040code_007bUSE_002c-INTRINSIC_007d-statement-298"></a><a name="index-statement_002c-_0040code_007bUSE_002c-INTRINSIC_007d-299"></a><a name="index-g_t_0040code_007bISO_005fFORTRAN_005fENV_007d-statement-300"></a><a name="index-statement_002c-_0040code_007bISO_005fFORTRAN_005fENV_007d-301"></a><code>USE</code> statement with <code>INTRINSIC</code> and <code>NON_INTRINSIC</code>
attribute; supported intrinsic modules: <code>ISO_FORTRAN_ENV</code>,
<code>ISO_C_BINDING</code>, <code>OMP_LIB</code> and <code>OMP_LIB_KINDS</code>.
<li>Renaming of operators in the <code>USE</code> statement.
</ul>
</body></html>
