// a struct of 256 bytes or more copied without the code saying so: a warning (the program still builds)
struct M4 {
    float a0
    float a1
    float a2
    float a3
    float b0
    float b1
    float b2
    float b3
    float c0
    float c1
    float c2
    float c3
    float d0
    float d1
    float d2
    float d3
}

struct Body {
    M4 world
    M4 local
    int id
}

fn weight(Body b) -> float {            // warned: 264 bytes copied on every call
    return b.world.a0 + float(b.id)
}

fn nudge(ptr[Body] b) {                 // shared: no warning
    b.world.a0 += 1.0
}

fn small(M4 m) -> float {               // 128 bytes: no warning
    return m.a0
}

fn main() {
    b := Body(id: 2)
    nudge(b)
    print(weight(b), small(b.world))
    bodies := [b, b]
    total := 0.0
    for x in bodies {                   // warned: each element copied into x
        total += x.world.a0
    }
    for i in 0..bodies.len {            // in place: no warning
        total += bodies[i].world.a0
    }
    print(total)
}