bloat-buster/tests/field_parent_pointer.bbb

S = struct
{
    a: u8,
    b: u32,
    c: u8,
}

assert = fn (ok: u1) void
{
    if (!ok) #trap();
}

[export] main = fn [cc(c)] () s32
{
    >s: S = {
        .a = 241,
        .b = 12356,
        .c = 128,
    };

    >p_a = &s.a;
    >p_a_struct: &S = #field_parent_pointer(p_a, "a");
    assert(p_a_struct == &s);
    assert(p_a_struct.a == s.a);
    assert(p_a_struct.b == s.b);
    assert(p_a_struct.c == s.c);
    
    >p_b = &s.b;
    >p_b_struct: &S = #field_parent_pointer(p_b, "b");
    assert(p_b_struct == &s);
    assert(p_b_struct.a == s.a);
    assert(p_b_struct.b == s.b);
    assert(p_b_struct.c == s.c);

    >p_c = &s.c;
    >p_c_struct: &S = #field_parent_pointer(p_c, "c");
    assert(p_c_struct == &s);
    assert(p_c_struct.a == s.a);
    assert(p_c_struct.b == s.b);
    assert(p_c_struct.c == s.c);

    return 0;
}