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<h3 class="section">7.1 Interoperability with C</h3>
<ul class="menu">
<li><a accesskey="1" href="Intrinsic-Types.html#Intrinsic-Types">Intrinsic Types</a>
<li><a accesskey="2" href="Derived-Types-and-struct.html#Derived-Types-and-struct">Derived Types and struct</a>
<li><a accesskey="3" href="Interoperable-Global-Variables.html#Interoperable-Global-Variables">Interoperable Global Variables</a>
<li><a accesskey="4" href="Interoperable-Subroutines-and-Functions.html#Interoperable-Subroutines-and-Functions">Interoperable Subroutines and Functions</a>
<li><a accesskey="5" href="Working-with-Pointers.html#Working-with-Pointers">Working with Pointers</a>
<li><a accesskey="6" href="Further-Interoperability-of-Fortran-with-C.html#Further-Interoperability-of-Fortran-with-C">Further Interoperability of Fortran with C</a>
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<p>Since Fortran 2003 (ISO/IEC 1539-1:2004(E)) there is a
standardized way to generate procedure and derived-type
declarations and global variables which are interoperable with C
(ISO/IEC 9899:1999). The <code>bind(C)</code> attribute has been added
to inform the compiler that a symbol shall be interoperable with C;
also, some constraints are added. Note, however, that not
all C features have a Fortran equivalent or vice versa. For instance,
neither C's unsigned integers nor C's functions with variable number
of arguments have an equivalent in Fortran.
<p>Note that array dimensions are reversely ordered in C and that arrays in
C always start with index 0 while in Fortran they start by default with
1. Thus, an array declaration <code>A(n,m)</code> in Fortran matches
<code>A[m][n]</code> in C and accessing the element <code>A(i,j)</code> matches
<code>A[j-1][i-1]</code>. The element following <code>A(i,j)</code> (C: <code>A[j-1][i-1]</code>;
assuming i < n) in memory is <code>A(i+1,j)</code> (C: <code>A[j-1][i]</code>).
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