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| <h4 class="subsection">7.1.1 Intrinsic Types</h4> |
| |
| <p>In order to ensure that exactly the same variable type and kind is used |
| in C and Fortran, the named constants shall be used which are defined in the |
| <code>ISO_C_BINDING</code> intrinsic module. That module contains named constants |
| for kind parameters and character named constants for the escape sequences |
| in C. For a list of the constants, see <a href="ISO_005fC_005fBINDING.html#ISO_005fC_005fBINDING">ISO_C_BINDING</a>. |
| </p> |
| <p>For logical types, please note that the Fortran standard only guarantees |
| interoperability between C99’s <code>_Bool</code> and Fortran’s <code>C_Bool</code>-kind |
| logicals and C99 defines that <code>true</code> has the value 1 and <code>false</code> |
| the value 0. Using any other integer value with GNU Fortran’s <code>LOGICAL</code> |
| (with any kind parameter) gives an undefined result. (Passing other integer |
| values than 0 and 1 to GCC’s <code>_Bool</code> is also undefined, unless the |
| integer is explicitly or implicitly casted to <code>_Bool</code>.) |
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