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<h4 class="subsection">7.1.2 Derived Types and struct</h4>
<p>For compatibility of derived types with <code>struct</code>, one needs to use
the <code>BIND(C)</code> attribute in the type declaration. For instance, the
following type declaration
<pre class="smallexample"> USE ISO_C_BINDING
TYPE, BIND(C) :: myType
INTEGER(C_INT) :: i1, i2
INTEGER(C_SIGNED_CHAR) :: i3
REAL(C_DOUBLE) :: d1
COMPLEX(C_FLOAT_COMPLEX) :: c1
CHARACTER(KIND=C_CHAR) :: str(5)
END TYPE
</pre>
<p>matches the following <code>struct</code> declaration in C
<pre class="smallexample"> struct {
int i1, i2;
/* Note: "char" might be signed or unsigned. */
signed char i3;
double d1;
float _Complex c1;
char str[5];
} myType;
</pre>
<p>Derived types with the C binding attribute shall not have the <code>sequence</code>
attribute, type parameters, the <code>extends</code> attribute, nor type-bound
procedures. Every component must be of interoperable type and kind and may not
have the <code>pointer</code> or <code>allocatable</code> attribute. The names of the
variables are irrelevant for interoperability.
<p>As there exist no direct Fortran equivalents, neither unions nor structs
with bit field or variable-length array members are interoperable.
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