c++ - erase-remove 习语 : did I just delete something?

Question

我正在使用 erase-remove 习语:

template <typename T>
bool garbageCollectVector(std::vector<T>& v) {
    // Use the erase-remove idiom in combination with a lambda expression
    v.erase(
        std::remove_if(v.begin(), v.end(),
            [this](const T& elem) -> bool {
                return this->shouldRemove(elem);
            }
        ),
        v.end());
    return /* what to return? */;
}

并希望返回该方法是否实际删除了任何元素。什么是最干净的方法？

Answer 1

除了大小检查，您还可以拆分您的实现:

template <typename T>
bool garbageCollectVector(std::vector<T>& v) {
    // Use the erase-remove idiom in combination with a lambda expression
    auto it = std::remove_if(v.begin(), v.end(),
                             [this](const T& elem) -> bool {
                                return this->shouldRemove(elem);
                             });
    if (it == v.end()) {
        return false;
    } else {
        v.erase(it, v.end());
        return true;
    }
}