# Objective
Unblocks #11659.
Currently the `Reflect` derive macro has to go through a merge process
for each `#[reflect]`/`#[reflet_value]` attribute encountered on a
container type.
Not only is this a bit inefficient, but it also has a soft requirement
that we can compare attributes such that an error can be thrown on
duplicates, invalid states, etc.
While working on #11659 this proved to be challenging due to the fact
that `syn` types don't implement `PartialEq` or `Hash` without enabling
the `extra-traits` feature.
Ideally, we wouldn't have to enable another feature just to accommodate
this one use case.
## Solution
Removed `ContainerAttributes::merge`.
This was a fairly simple change as we could just have the parsing
functions take `&mut self` instead of returning `Self`.
## Testing
CI should build as there should be no user-facing change.
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