(void)ptr 的作用

Question

在 FlatBuffers 的示例中看见这样的写法，没明白为什么这么写？
sample_binary.cpp

  // Get a test an element from the `inventory` FlatBuffer's `vector`.
  auto inv = monster->inventory();
  assert(inv);
  assert(inv->Get(9) == 9);
  (void)inv;

  // Get and test the `weapons` FlatBuffers's `vector`.
  std::string expected_weapon_names[] = {"Sword", "Axe"};
  short expected_weapon_damages[] = {3, 5};
  auto weps = monster->weapons();
  for (unsigned int i = 0; i < weps->size(); i++) {
    assert(weps->Get(i)->name()->str() == expected_weapon_names[i]);
    assert(weps->Get(i)->damage() == expected_weapon_damages[i]);
  }
  (void)expected_weapon_names;
  (void)expected_weapon_damages;

Answer 1

这种东西看一下 commit 内容就知道了，就是silence compiler warning。
https://github.com/google/fla...
https://github.com/google/fla...