Support Coercing an Anonymous Struct Literal to an Error Union

[ominitay]

Disclaimer: This is kind-of a proposal and kind-of a bug, so I'm not sure how this should be labelled.

The Problem

Presently, attempting to return a struct from a fallible function using an anonymous struct literal will fail, with the error: type 'ErrorSet!StructType' does not support struct initialization syntax. I believe this to be a deficiency in the current implementation of Zig, especially if #5038 were to be accepted and implemented. The current behaviour is an unnecessary implementation as far as I can tell, and makes code more verbose than necessary or desirable.

The Solution

There are two possible solutions here. Firstly, to simply allow this coercion to be made. I don't see any fundamental contradictions here which would prevent this from working. Alternatively, #7812 would also address this, as returning values would be separated from throwing errors.

cc: @gracefuu
related: #5038 #7812

[Vexu]

Something like this #10925?

[nektro]

yeah this is fixed in stage2. it was a limitation of the stage1 coercing checks but an easy fix since .{ } can never be an error value.

[ominitay]

Glad to see it's fixed in the self-hosted compiler! Apologies for opening this then, but GitHub's search feature isn't so helpful...