自定义trie容器插入r值语义

Question

我的插入成员函数有以下声明：

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一旦我实现了移动（＆amp;＆amp;）版本，它就是唯一一个被调用的版本。我试图通过以下单元测试。

std::pair<iterator, bool> insert(value_type const& pair);
std::pair<iterator, bool> insert(value_type&& pair);

但它正在呼唤＆amp;＆amp;功能不是const＆amp;一。不确定为什么const＆amp;永远不会被称为。

如果我删除＆amp;＆amp;实现const＆amp;被叫，我通过了单元测试。

使用以下内容会产生什么副作用：

using mapped_t = std::string;
using vector_t = std::vector<mapped_t>;
using trie_t = trie<mapped_t>;
using key_t = trie_t::key_type;
using map_t = std::map<key_t, mapped_t>;

vector_t data{ "nine", "ten", "seven", "eight", "five", "six", "three", "four", "one", "two" };
map_t m;
trie_t t;
for (auto datum : data) {
    t.insert(trie_t::value_type(datum, datum));
    m.insert(map_t::value_type(datum, datum));
}

BOOST_CHECK(std::equal(t.begin(), t.end(), m.begin()));
BOOST_CHECK(t.size() == m.size());