<p>I'm trying to extend an ODM and one of the methods will require me to return an error if an anonymous struct is passed. I can't just check against .Kind() using reflect.Struct since non-anonymous structs are handled a different way. </p>
<p>Any ideas how I can do this without falling back to an awful string comparison against reflect.TypeOf(<var>).String()?</p>
<p>Thanks.</p>
<hr/>**评论：**<br/><br/>matttproud: <pre><p>I would expect that the package path for an anonymous struct would be empty or contain some other sentinel value:</p>
<pre><code>t := reflect.TypeOf(struct{ field string }{})
fmt.Println(t.PkgPath() == "")
</code></pre>
<p>… and it turns out this is the case: <a href="http://play.golang.org/p/GDHCkMXTzy" rel="nofollow">http://play.golang.org/p/GDHCkMXTzy</a>. However, this feels fragile to me, something liable to break in the future, because nothing in the specification speaks to this behavior.</p>
<p>Further: this pattern works only if the type is <em>truly anonymous</em>. If you create <em>named type within the scope of a function</em>, it has both a name and a package path.</p></pre>JakeTheDev: <pre><p>I never thought about trying it this way. It still feels incredibly dirty, but less so than a string.Contains() against TypeOf().String().</p>
<p>In my specific case, I only need to handle this if it <em>is</em> truly anonymous, so this concept will work for now. I wonder if the developers of Golang will improve the reflect package to allow an approach that ensures a bit more integrity.</p>
<p>Thanks for your suggestion.</p></pre>klauspost: <pre><p>It is perfectly valid, and I would expect it to remain as such for Go 1.x. Anonumous structs will not suddenly be exported. However it will also be true if the passed struct type is just unexported.</p>
<p>Here is some code that analyzes fields in a struct: <a href="http://play.golang.org/p/QjixAKL6_Q" rel="nofollow">http://play.golang.org/p/QjixAKL6_Q</a></p></pre>
