- Start Date: 2014-09-30
- RFC PR: rust-lang/rfcs#341
- Rust Issue: rust-lang/rust#17861
Removes the "virtual struct" (aka struct inheritance) feature, which is currently feature gated.
Virtual structs were added experimentally prior to the RFC process as a way of inheriting fields from one struct when defining a new struct.
The feature was introduced and remains behind a feature gate.
The motivations for removing this feature altogether are:
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The feature is likely to be replaced by a more general mechanism, as part of the need to address hierarchies such as the DOM, ASTs, and so on. See this post for some recent discussion.
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The implementation is somewhat buggy and incomplete, and the feature is not well-documented.
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Although it's behind a feature gate, keeping the feature around is still a maintenance burden.
Remove the implementation and feature gate for virtual structs.
Retain the virtual keyword as reserved for possible future use.
The language will no longer offer any built-in mechanism for avoiding repetition of struct fields. Macros offer a reasonable workaround until a more general mechanism is added.
None known.