Crate ommx_derive 

Derive macros for the ommx crate.

This crate exists solely as an implementation detail of ommx: it is published to crates.io because ommx depends on it, but it has no stable API of its own and no public surface for external use.

The ommx crate gates the LogicalMemoryProfile trait and the re-exported derive behind a pub(crate) module, so downstream users cannot reach them through the public API and cannot meaningfully derive on their own types. The trait and the re-export are declared pub inside that module to satisfy the private_bounds lint when the trait appears in the bound of a pub type within the crate (e.g. ConstraintMetadataStore<ID: ... + LogicalMemoryProfile>). External consumers should use ommx::Instance::logical_memory_profile and ommx::MemoryProfile instead.

#[derive(LogicalMemoryProfile)]

Generates a LogicalMemoryProfile impl that delegates to each field of a named-field struct. Each field is emitted under the path frame "TypeName.field_name". The ommx crate uses this derive at every struct definition that participates in memory profiling, so that adding or removing a field automatically adjusts the profile.

Supported

• Structs with named fields.
  • All fields must implement LogicalMemoryProfile. Primitives, String, Option<T>, Vec<T>, BTreeMap, HashMap, FnvHashMap, and BTreeSet all have blanket impls in ommx::logical_memory::collections.
• Generic structs: type parameters are propagated through, but no LogicalMemoryProfile bound is added automatically. The struct must declare its own where T: LogicalMemoryProfile clause. This matches serde’s historical #[serde(bound = ...)] philosophy — the derive does not guess.

Not supported

• Tuple structs and unit structs → emit a compile_error! directing the caller to a hand-written impl.
• Enums → emit a compile_error!. For enums, hand-write a match (Function in the ommx crate is an example).
• Field skipping → there is no #[logical_memory(skip)] attribute. If a field truly should not participate, hand-write the impl.
• Custom frame names → the frame is always "TypeName.field_name" taken from the struct ident and field ident. For a renamed frame (e.g. when wrapping an external type), use the declarative impl_logical_memory_profile! { path::to::Type as "Name" { ... } } form instead.

Testing

The proc-macro entry point delegates to derive_logical_memory_profile_impl, a pure TokenStream2 -> TokenStream2 function. This is exercised by inline insta snapshot tests in this crate — the generated code is checked in as a snapshot so any drift is caught at review time.

Derive Macros

LogicalMemoryProfile

Derive LogicalMemoryProfile for a struct by delegating to each field.