S0058: Shared handle cannot be stored in state

Generated from rellum-diagnostics/src/db.rs.

Explanation

Shared[T] handles are tick-scoped aliases created so Move values can be read by multiple consumers within one tick. Storing a Shared[T] handle in ~ state would let it outlive the tick that created it, which would make later ticks read an invalid handle.

Common causes

• using share(value) as a ~ state initial value
• returning share(value) from a feedback clause
• annotating state as Shared[T]

Canonical fixes

• store the owned value or a Copy projection instead of the Shared handle

Before:

history ~ feedback(
    on line => share(line),
    share("")
)

After:

history ~ feedback(
    on line => line,
    ""
)

• create Shared[T] handles only at the use sites within the same tick

Code example

history ~ feedback(
    on line => share(line),
    share("")
)

Links

• RellC diagnostic overview