<dl id="errors"><dt><a href="/pkg/errors/">errors</a></dt>
<dd>
- <p><!-- https://go.dev/issue/41198 -->
- TODO: <a href="https://go.dev/issue/41198">https://go.dev/issue/41198</a>: add ErrUnsupported
- </p>
-
- <p><!-- CL 473935 -->
- TODO: <a href="https://go.dev/cl/473935">https://go.dev/cl/473935</a>: errors: add ErrUnsupported; modified api/next/41198.txt
+ <p><!-- https://go.dev/issue/41198, CL 473935 -->
+ The new
+ <a href="/pkg/errors/#ErrUnsupported"><code>ErrUnsupported</code></a>
+ error provides a standardized way to indicate that a requested
+ operation may not be performed because it is unsupported.
+ For example, a call to
+ <a href="/pkg/os/#Link"><code>os.Link</code></a> when using a
+ file system that does not support hard links.
</p>
</dd>
</dl><!-- errors -->
</p>
<p><!-- CL 494122 -->
- TODO: <a href="https://go.dev/cl/494122">https://go.dev/cl/494122</a>: net/http: let ErrNotSupported match errors.ErrUnsupported; modified api/next/41198.txt
+ The <a href="/pkg/net/http/">net/http</a> package now supports
+ <a href="/pkg/errors/#ErrUnsupported"><code>errors.ErrUnsupported</code></a>,
+ in that the expression
+ <code>errors.Is(http.ErrNotSupported, errors.ErrUnsupported)</code>
+ will return true.
</p>
</dd>
</dl><!-- net/http -->
This is backward compatible as WTF-8 is a superset of the UTF-8
format that was used in earlier releases.
</p>
+
+ <p><!-- CL 476578, CL 476875, CL 476916 -->
+ Several error values match the new
+ <a href="/pkg/errors/#ErrUnsupported"><code>errors.ErrUnsupported</code></a>,
+ such that <code>errors.Is(err, errors.ErrUnsupported)</code>
+ returns true.
+ <ul>
+ <li><code>ENOSYS</code></li>
+ <li><code>ENOTSUP</code></li>
+ <li><code>EOPNOTSUPP</code></li>
+ <li><code>EPLAN9</code> (Plan 9 only)</li>
+ <li><code>ERROR_CALL_NOT_IMPLEMENTED</code> (Windows only)</li>
+ <li><code>ERROR_NOT_SUPPORTED</code> (Windows only)</li>
+ <li><code>EWINDOWS</code> (Windows only)</li>
+ </ul>
+ </p>
</dd>
</dl><!-- syscall -->