static bool _swap_monsters(const int mover_idx, const int moved_idx)
{
    monsters* mover = &menv[mover_idx];
    monsters* moved = &menv[moved_idx];
    // Can't swap with a stationary monster.
    if (mons_is_stationary(moved))
        return false;
    // Swapping is a purposful action
    if (mover->confused())
        return false;
    // Right now just happens in sanctuary
    if (!is_sanctuary(mover->x, mover->y) || !is_sanctuary(moved->x, moved->y))
        return false;

    // A friendly or good-neutral monster moving past a fleeing hostile
    // or neutral monster, or visa-versa
    if (mons_wont_attack(mover) == mons_wont_attack(moved)
        || mons_is_fleeing(mover) == mons_is_fleeing(moved))
    {
        return false;
    }
    if (!mover->can_pass_through(moved->x, moved->y)
        || !moved->can_pass_through(mover->x, mover->y))
    {
        return false;
    }
    if (!monster_habitable_grid(mover, grd[moved->x][moved->y])
        || !monster_habitable_grid(moved, grd[mover->x][mover->y]))
    {
        return false;
    }
    // Okay, we can do the swap.
    const coord_def mover_pos = mover->pos();
    const coord_def moved_pos = moved->pos();
    mover->x = moved_pos.x;
    mover->y = moved_pos.y;
  
    moved->x = mover_pos.x;
    moved->y = mover_pos.y;
    mgrd(mover->pos()) = mover_idx;
    mgrd(moved->pos()) = moved_idx;
    if (you.can_see(mover) && you.can_see(moved))
    {
        mprf("%s and %s swap places.", mover->name(DESC_CAP_THE).c_str(),
             moved->name(DESC_NOCAP_THE).c_str());
    }
    return true;
} // bool _swap_monsters()

                // Maybe they can swap places?
                if (_swap_monsters(i, targmon))
                {
                    _swim_or_move_energy(monster);
                    continue;
                }

                if (monsters_fight(i, targmon))

                else if (monsters_fight(i, targmon))

                                 && !mons_is_stationary(&menv[targ_monst])