Constraint missing (async function must return one of these types) in draft C# specification about csharplang HOT 4 CLOSED

@axel-habermaier, I understand that.

I'm looking at the specification. The _inferred return type_ is not defined until §7.5, and anonymous function expressions in §7.15 which points to §10.14, it should be §10.15, which states that void, Task and Task<T> are the valid async method return types.

However, §6.5 already points to §7.15, and a couple of §7.15's subchapters point back to §6.5.

Perhaps what should be discussed is not the lack of constraints, but if repeating/reminding/introducing the valid async return types is useful in §6.5, more than just linking to other chapters.

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How should this not be forbidden? None of the implicit async return types (void, Task or Task<TResult>) is compatible with int.

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@acelent: Yes, that's why @gafter thinks the specification must be fixed. In order words: The compiler is right, the spec is (probably) wrong.

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This was addressed in the C# 5.0 standard in §15.15.1.

Closing.

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