Fix #13

.devel/sphinx/_build/html/genindex.html

@@ -264,7 +264,7 @@ <h1 id="index">Index</h1>
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/index.html

@@ -283,7 +283,7 @@ <h1>stringx: Replacements for base R string functions powered by stringi<a class
 <p>To learn more about R, check out Marek’s open-access (free!) textbook
 <a class="reference external" href="https://deepr.gagolewski.com/">Deep R Programming</a>.</p>
 </div>
-<p><strong>stringx brings R string processing abilities into the 21st century.</strong>
+<p><strong>stringx brings R string processing abilities to the 21st century.</strong>
 It replaces functions like <strong class="command">paste</strong>, <strong class="command">grep</strong>,
 <strong class="command">tolower</strong>, <strong class="command">strptime</strong>, and <strong class="command">sprintf</strong>
 with ones that:</p>
@@ -391,7 +391,7 @@ <h1>stringx: Replacements for base R string functions powered by stringi<a class
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/news.html

@@ -259,39 +259,40 @@ <h1>Changelog<a class="headerlink" href="#changelog" title="Link to this heading
 in progress. Feature requests/comments/remarks are welcome,
 see <a class="reference external" href="https://github.com/gagolews/stringx/issues">https://github.com/gagolews/stringx/issues</a>.</p>
 </div></blockquote>
-<section id="in-progress">
-<h2>0.2.6 (in progress)<a class="headerlink" href="#in-progress" title="Link to this heading">#</a></h2>
+<section id="id1">
+<h2>0.2.6 (2023-11-30)<a class="headerlink" href="#id1" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>[BACKWARD INCOMPATIBILITY] <code class="docutils literal notranslate"><span class="pre">strptime</span></code> fills missing fields based
 on today’s midnight, due to a change in <em>stringi</em>-1.8.1.</p></li>
+<li><p>[BUGFIX] #13: Subtracting of objects of class <code class="docutils literal notranslate"><span class="pre">POSIXxt</span></code> resulted in an error.</p></li>
 </ul>
 </section>
-<section id="id1">
-<h2>0.2.5 (2023-05-21)<a class="headerlink" href="#id1" title="Link to this heading">#</a></h2>
+<section id="id2">
+<h2>0.2.5 (2023-05-21)<a class="headerlink" href="#id2" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>[BUGFIX] Fixed failing checks/tests due to some updates in R.</p></li>
 </ul>
 </section>
-<section id="id2">
-<h2>0.2.4 (2022-10-27)<a class="headerlink" href="#id2" title="Link to this heading">#</a></h2>
+<section id="id3">
+<h2>0.2.4 (2022-10-27)<a class="headerlink" href="#id3" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>[BUGFIX] Fixed failing checks/tests due to some updates in R.</p></li>
 </ul>
 </section>
-<section id="id3">
-<h2>0.2.3 (2022-10-13)<a class="headerlink" href="#id3" title="Link to this heading">#</a></h2>
+<section id="id4">
+<h2>0.2.3 (2022-10-13)<a class="headerlink" href="#id4" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>[BUGFIX] Fixed failing checks/tests due to some updates in R.</p></li>
 </ul>
 </section>
-<section id="id4">
-<h2>0.2.2 (2021-09-03)<a class="headerlink" href="#id4" title="Link to this heading">#</a></h2>
+<section id="id5">
+<h2>0.2.2 (2021-09-03)<a class="headerlink" href="#id5" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>[DOCUMENTATION] ICU Project site has been moved to <a class="reference external" href="https://icu.unicode.org/">https://icu.unicode.org/</a>.</p></li>
 </ul>
 </section>
-<section id="id5">
-<h2>0.2.1 (2021-08-27)<a class="headerlink" href="#id5" title="Link to this heading">#</a></h2>
+<section id="id6">
+<h2>0.2.1 (2021-08-27)<a class="headerlink" href="#id6" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>[BACKWARD INCOMPATIBILITY, BUGFIX] #7: Dates without times are now always
 treated as being at midnight in the local (default) time zone.</p></li>
@@ -305,21 +306,21 @@ <h2>0.2.1 (2021-08-27)<a class="headerlink" href="#id5" title="Link to this head
 <code class="docutils literal notranslate"><span class="pre">c.POSIXxt</span></code>, <code class="docutils literal notranslate"><span class="pre">rep.POSIXxt</span></code>, <code class="docutils literal notranslate"><span class="pre">seq.POSIXxt</span></code>.</p></li>
 </ul>
 </section>
-<section id="id6">
-<h2>0.1.3 (2021-08-05)<a class="headerlink" href="#id6" title="Link to this heading">#</a></h2>
+<section id="id7">
+<h2>0.1.3 (2021-08-05)<a class="headerlink" href="#id7" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>[BUGFIX] #4: Fixed failing check with ICU 55.</p></li>
 <li><p>[BUGFIX] #5: Fixed failing check under POSIX/C locale.</p></li>
 </ul>
 </section>
-<section id="id7">
-<h2>0.1.2 (2021-07-27)<a class="headerlink" href="#id7" title="Link to this heading">#</a></h2>
+<section id="id8">
+<h2>0.1.2 (2021-07-27)<a class="headerlink" href="#id8" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>First <a class="reference external" href="https://cran.r-project.org/package=stringx">CRAN</a> release.</p></li>
 </ul>
 </section>
-<section id="id8">
-<h2>0.1.1 (2021-07-15)<a class="headerlink" href="#id8" title="Link to this heading">#</a></h2>
+<section id="id9">
+<h2>0.1.1 (2021-07-15)<a class="headerlink" href="#id9" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>[GENERAL] <a class="reference external" href="https://stringx.gagolewski.com/">On-line manual</a> is now available.</p></li>
 <li><p>[GENERAL] Using <a class="reference external" href="https://realtest.gagolewski.com/"><em>realtest</em></a>
@@ -361,8 +362,8 @@ <h2>0.1.1 (2021-07-15)<a class="headerlink" href="#id8" title="Link to this head
 <code class="docutils literal notranslate"><span class="pre">regexec</span></code>, <code class="docutils literal notranslate"><span class="pre">gregexec</span></code>.</p></li>
 </ul>
 </section>
-<section id="id9">
-<h2>0.0.0 (2021-05-07)<a class="headerlink" href="#id9" title="Link to this heading">#</a></h2>
+<section id="id10">
+<h2>0.0.0 (2021-05-07)<a class="headerlink" href="#id10" title="Link to this heading">#</a></h2>
 <ul class="simple">
 <li><p>The <em>stringx</em> project has been started.</p></li>
 </ul>
@@ -396,7 +397,7 @@ <h2>0.0.0 (2021-05-07)<a class="headerlink" href="#id9" title="Link to this head
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>
@@ -418,16 +419,16 @@ <h2>0.0.0 (2021-05-07)<a class="headerlink" href="#id9" title="Link to this head
           <div class="toc-tree">
             <ul>
 <li><a class="reference internal" href="#">Changelog</a><ul>
-<li><a class="reference internal" href="#in-progress">0.2.6 (in progress)</a></li>
-<li><a class="reference internal" href="#id1">0.2.5 (2023-05-21)</a></li>
-<li><a class="reference internal" href="#id2">0.2.4 (2022-10-27)</a></li>
-<li><a class="reference internal" href="#id3">0.2.3 (2022-10-13)</a></li>
-<li><a class="reference internal" href="#id4">0.2.2 (2021-09-03)</a></li>
-<li><a class="reference internal" href="#id5">0.2.1 (2021-08-27)</a></li>
-<li><a class="reference internal" href="#id6">0.1.3 (2021-08-05)</a></li>
-<li><a class="reference internal" href="#id7">0.1.2 (2021-07-27)</a></li>
-<li><a class="reference internal" href="#id8">0.1.1 (2021-07-15)</a></li>
-<li><a class="reference internal" href="#id9">0.0.0 (2021-05-07)</a></li>
+<li><a class="reference internal" href="#id1">0.2.6 (2023-11-30)</a></li>
+<li><a class="reference internal" href="#id2">0.2.5 (2023-05-21)</a></li>
+<li><a class="reference internal" href="#id3">0.2.4 (2022-10-27)</a></li>
+<li><a class="reference internal" href="#id4">0.2.3 (2022-10-13)</a></li>
+<li><a class="reference internal" href="#id5">0.2.2 (2021-09-03)</a></li>
+<li><a class="reference internal" href="#id6">0.2.1 (2021-08-27)</a></li>
+<li><a class="reference internal" href="#id7">0.1.3 (2021-08-05)</a></li>
+<li><a class="reference internal" href="#id8">0.1.2 (2021-07-27)</a></li>
+<li><a class="reference internal" href="#id9">0.1.1 (2021-07-15)</a></li>
+<li><a class="reference internal" href="#id10">0.0.0 (2021-05-07)</a></li>
 </ul>
 </li>
 </ul>

.devel/sphinx/_build/html/rapi.html

@@ -298,7 +298,7 @@ <h1>R Package <em>stringx</em> Reference<a class="headerlink" href="#r-package-s
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/ISOdatetime.html

@@ -382,7 +382,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/about_stringx.html

@@ -311,7 +311,7 @@ <h2>See Also<a class="headerlink" href="#see-also" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/chartr.html

@@ -397,7 +397,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/constants.html

@@ -386,7 +386,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/gregexpr.html

@@ -558,7 +558,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/gregextr.html

@@ -452,7 +452,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/grepl.html

@@ -428,7 +428,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/gsub.html

@@ -420,7 +420,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/nchar.html

@@ -374,7 +374,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/paste.html

@@ -458,7 +458,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/sort.html

@@ -459,7 +459,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/sprintf.html

@@ -388,7 +388,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/startswith.html

@@ -407,7 +407,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>

.devel/sphinx/_build/html/rapi/strcoll.html

@@ -404,7 +404,7 @@ <h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">
               Some rights reserved. Licensed under <a href='https://creativecommons.org/licenses/by-nc-nd/4.0/'>CC BY-NC-ND 4.0</a>.
               Built with <a href="https://sphinx-doc.org/">Sphinx</a>
               and a customised <a href="https://github.com/pradyunsg/furo">Furo</a> theme.
-              Last updated on 2023-11-16T10:39:44+1100.
+              Last updated on 2023-11-30T09:13:19+1100.
               This site will never display any ads: it is a non-profit project.
               It does not collect any data.
             </div>