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POWhat is the appropriate way to strongly type the return of a generic function?
 

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    <p>I'm writing a filter function to return the specific type specified out of a larger collection of supertypes (objects for example). The idea is I give you an enumerable and you return me all the strings for example. you can write it this way without generics:</p> <pre><code>public static IEnumerable Filter(IEnumerable source, Type type) { List&lt;object&gt; results = new List&lt;object&gt;(); foreach(object o in source) { if(o != null &amp;&amp; o.GetType() == type) { results.Add(o); } } return results; } </code></pre> <p>if we want to return generics there are a few different ways to go about it.</p> <p>As a straight port:</p> <pre><code>public static IEnumerable&lt;TResult&gt; Filter&lt;TResult&gt; (IEnumerable source, Type type) </code></pre> <p>Pass in an 'example':</p> <pre><code>IEnumerable&lt;TResult&gt; Filter&lt;TResult&gt; (IEnumerable source, TResult resultType) </code></pre> <p>Ultimately what I think is cleanest:</p> <pre><code>public static IEnumerable&lt;T&gt; Filter&lt;T&gt;(IEnumerable source) </code></pre> <p>The second type would be called entirely with parameters (and infer the type):</p> <pre><code>Filter(myList, "exampleString"); </code></pre> <p>where as the final version there would get called with a type specifier:</p> <pre><code>Filter&lt;string&gt;(myList); </code></pre> <p>What is the appropriate way to strongly type the return of a generic function, where the return type isn't automatically implied in the signature? (why?)</p> <p>(Edit Note: Our input is NOT typed, e.g. IEnumerable&lt;T&gt;. At best it would be IEnumerable. This function is returning the Ts out of the whole collection of other types.)</p>
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