725a7b6551
A native C++ binding generator (`cpp_native.nim`), the C++ counterpart of the C
and Go native paths and companion to the CBOR `cpp.nim`. It emits
`<lib>_native.hpp`: an idiomatic C++ struct + `toC`/`fromC` per `{.ffi.}` type,
and a `<Lib>Node` class whose methods marshal typed args into / read typed
struct returns out of the native ABI (`<name>` entry points + flat C structs in
`<lib>.h`) — zero serialization. Wired into genBindings under
`targetLang=cpp` + `-d:ffiMode=native`; emits the native C header alongside so
the binding is self-contained. Task: `genbindings_cpp_native`.
First cut covers scalar/string/bool/nested-struct fields (create/version/echo);
seq/Option params are `// SKIPPED`, and native typed events are next. Filename
is `_native.hpp` for now to coexist with the CBOR `.hpp` (rename is a follow-up).
Verified end-to-end: the generated example builds and round-trips a typed
EchoResponse (`make run`).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
timer example
This example is a self-contained Nimble project demonstrating how to import nim-ffi and use the .ffiCtor. / .ffi. abstraction.
Two ABIs, one library
Every generated library exports two ABIs side by side, and you choose per call site:
| ABI | Header / symbols | Use it for |
|---|---|---|
| Native (pure C) | <lib>.h / <name> |
Same-process / local calls. Flat C structs by value, zero serialization. |
| CBOR | <lib>_cbor.h / <name>_cbor |
Inter-process communication only — a different process or machine, where the request must be serialized to cross the boundary. |
In a shared address space the CBOR round-trip is pure overhead, so default to the native ABI locally and reach for CBOR only when you actually cross a process/machine boundary (see ipc/). The per-language examples below: native C (c_bindings/), native Go (go_bindings/), native/CBOR C++ (cpp_bindings/), CBOR Rust (rust_client/), and CBOR-over-socket IPC (ipc/).
Usage
-
Change into the example directory:
cd examples/timer -
Install the local
ffidependency:nimble install -y ../.. -
Build the example library:
nimble build -
Generate bindings:
nimble genbindings_rust nimble genbindings_cpp
Rust example clients
The Rust client lives in examples/timer/rust_client.
-
Run the sync example:
cd examples/timer/rust_client cargo run --bin rust_client -
Run the Tokio example:
cd examples/timer/rust_client cargo run --bin tokio_client
C++ example
The generated C++ example lives in examples/timer/cpp_bindings.
Build and run it with:
cd examples/timer/cpp_bindings
cmake -S . -B build
cmake --build build
./build/example