Attribute Macro safer_ffi::derive_ReprC

#[derive_ReprC]

Safely implement ReprC for a #[repr(C)] struct when all its fields are ReprC.

Examples

Simple struct

use ::safer_ffi::prelude::*;

#[derive_ReprC]
#[repr(C)]
struct Instant {
    seconds: u64,
    nanos: u32,
}

• corresponding to the following C definition:

  typedef struct {
      uint64_t seconds;
      uint32_t nanos;
  } Instant_t;
  

Field-less enum

use ::safer_ffi::prelude::*;

#[derive_ReprC]
#[repr(u8)]
enum Status {
    Ok = 0,
    Busy,
    NotInTheMood,
    OnStrike,
    OhNo,
}

• corresponding to the following C definition:

  typedef uint8_t Status_t; enum {
      STATUS_OK = 0,
      STATUS_BUSY,
      STATUS_NOT_IN_THE_MOOD,
      STATUS_ON_STRIKE,
      STATUS_OH_NO,
  }
  

Generic struct

In that case, it is required that the struct’s generic types carry a : ReprC bound each:

use ::safer_ffi::prelude::*;

#[derive_ReprC]
#[repr(C)]
struct Point<Coordinate : ReprC> {
    x: Coordinate,
    y: Coordinate,
}

Each monomorphization leads to its own C definition:

• Point<i32>

  typedef struct {
      int32_t x;
      int32_t y;
  } Point_int32_t;
  

• Point<f64>

  typedef struct {
      double x;
      double y;
  } Point_double_t;