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| <h3 class="section">6.4 Non-reentrant Conversion Function</h3> |
| |
| <p>The functions described in the previous chapter are defined in |
| Amendment 1<!-- /@w --> to ISO C90<!-- /@w -->, but the original ISO C90<!-- /@w --> standard |
| also contained functions for character set conversion. The reason that |
| these original functions are not described first is that they are almost |
| entirely useless. |
| |
| <p>The problem is that all the conversion functions described in the |
| original ISO C90<!-- /@w --> use a local state. Using a local state implies that |
| multiple conversions at the same time (not only when using threads) |
| cannot be done, and that you cannot first convert single characters and |
| then strings since you cannot tell the conversion functions which state |
| to use. |
| |
| <p>These original functions are therefore usable only in a very limited set |
| of situations. One must complete converting the entire string before |
| starting a new one, and each string/text must be converted with the same |
| function (there is no problem with the library itself; it is guaranteed |
| that no library function changes the state of any of these functions). |
| <strong>For the above reasons it is highly requested that the functions |
| described in the previous section be used in place of non-reentrant |
| conversion functions.</strong> |
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| <li><a accesskey="1" href="Non_002dreentrant-Character-Conversion.html#Non_002dreentrant-Character-Conversion">Non-reentrant Character Conversion</a>: Non-reentrant Conversion of Single |
| Characters. |
| <li><a accesskey="2" href="Non_002dreentrant-String-Conversion.html#Non_002dreentrant-String-Conversion">Non-reentrant String Conversion</a>: Non-reentrant Conversion of Strings. |
| <li><a accesskey="3" href="Shift-State.html#Shift-State">Shift State</a>: States in Non-reentrant Functions. |
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