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// This example demonstrates how to write interface decorators.
#include <interface99.h>
#include <stdio.h>
#define Vehicle_IFACE \
vfunc(void, refuel, VSelf, int fuel) \
vfunc(void, drive, VSelf)
interface(Vehicle);
// Car implementation
// ============================================================
typedef struct {
int fuel;
} Car;
void Car_refuel(VSelf, int fuel) {
VSELF(Car);
self->fuel += fuel;
}
void Car_drive(VSelf) {
VSELF(Car);
self->fuel--;
}
impl(Vehicle, Car);
// TracingVehicle implementation
// ============================================================
typedef struct {
Vehicle inner;
} TracingVehicle;
void TracingVehicle_refuel(VSelf, int fuel) {
VSELF(TracingVehicle);
printf("Vehicle.refuel(%d)\n", fuel);
VCALL(self->inner, refuel, fuel);
}
void TracingVehicle_drive(VSelf) {
VSELF(TracingVehicle);
printf("Vehicle.drive()\n");
VCALL(self->inner, drive);
}
impl(Vehicle, TracingVehicle);
// Test
// ============================================================
void test(Vehicle vehicle) {
VCALL(vehicle, refuel, 15);
VCALL(vehicle, drive);
}
/*
* Output:
* Vehicle.refuel(15)
* Vehicle.drive()
*/
int main(void) {
Vehicle car = DYN_LIT(Car, Vehicle, {.fuel = 0});
Vehicle tracing_car = DYN_LIT(TracingVehicle, Vehicle, {.inner = car});
test(tracing_car);
return 0;
}
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