c# - Creating an extension method to wrap types as IEnumerables -

i wanted create extension method efficiently wrap single objects ienumerables. avoid cases end putting new [] {} in middle of expression. easy enough using following method:

public static ienumerable<tsource> wrapasenumerable<tsource>(this tsource source) {     return new[] { source }; } 

the problem applied , types (which expected behavior), have side effect of making method available on ienumerable <t> instances. in case resolved extended type ienumerable<t>, return ienumerable, since aternative finding myself ienumerable<ienumerable<t>>, not you'd expect when calling method.

instinctively (and perhaps sleepily), first created overload looked this

public static ienumerable<tsource> wrapasenumerable<tsource>(this ienumerable<tsource> source) {     return source; } 

in order handle case type wrap ienumerable<t>, of course, control flow resolves first method.

so, question is: how create such wrapping method handles both case extended parameter instance ienumerable<t> , when not ?

here attempt, inspired eric lippert's excellent post at: https://stackoverflow.com/a/1451184/4955425.

you can control overloading resolution placing 2 extension methods @ different levels in namespace hierarchy.

namespace myextensions {     public static class highprecendenceextensions     {         public static ienumerable<tsource> wrapasenumerable<tsource>(this ienumerable<tsource> source)         {             return source;         }     }      namespace lowerprecedencenamespace     {         public static class lowprecedenceextensions         {             public static ienumerable<tsource> wrapasenumerable<tsource>(this tsource source)             {                 return new[] { source };             }         }     } } 

however, downside you'll need refer both namespaces right method invocation behavior.

using myextensions; using myextensions.lowerprecedencenamespace;