Ivan FB 03c9cbea36
docs(examples): add native (same-process) C++ example
Complements the CBOR C++ bindings (../cpp_bindings) with the native path: a C++
program that links the library and calls the native `<name>` ABI directly,
passing {.ffi.} structs by value and reading typed struct returns
(EchoResponse) from the callback — no CBOR, no tinycbor. An RAII TimerNode
wrapper bridges the async FFI-thread callback to a synchronous API via
std::future. README spells out native (same-process) vs CBOR (IPC). Verified
end-to-end with `make run`.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-05-31 18:37:20 +02:00
..
2026-05-25 15:51:56 +02:00
2026-05-21 16:33:38 +02:00

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

  1. Change into the example directory:

    cd examples/timer
    
  2. Install the local ffi dependency:

    nimble install -y ../..
    
  3. Build the example library:

    nimble build
    
  4. 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