Bug 33982 - Dynamic object changes behaviour of generic method
Summary: Dynamic object changes behaviour of generic method
Alias: None
Product: Compilers
Classification: Mono
Component: C# ()
Version: 4.0.0
Hardware: PC Linux
: --- normal
Target Milestone: ---
Assignee: Marek Safar
Depends on:
Reported: 2015-09-15 15:11 UTC by Michael de Lang
Modified: 2015-09-16 04:24 UTC (History)
2 users (show)

Is this bug a regression?: ---
Last known good build:

.cs file showcasing the problem (286 bytes, text/x-csharp)
2015-09-15 15:11 UTC, Michael de Lang

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Description Michael de Lang 2015-09-15 15:11:17 UTC
See attachment.

I expect a compiler error about not being able to implicitly convert an int to a string, but instead, the function returns a dynamic object, which is different from the method specification.
Comment 1 Michael de Lang 2015-09-15 15:11:56 UTC
Created attachment 12901 [details]
.cs file showcasing the problem
Comment 2 Michael de Lang 2015-09-15 15:25:05 UTC
Compile using mcs /target:library BuggyClass.cs
Running is not relevant.
Mono C# compiler version
Comment 3 Marek Safar 2015-09-16 04:24:57 UTC
That's feature of dynamic binder. You are passing a dynamic object in which in this case is ExpandoObject but that's not known to compiler and it can be anything therefore this method may not even match. You get correct error during execution when the actual overload resolution happens