如何将从ifstream读取的数据转换为vector<T>

Question

我有这样的代码，它从ifstream中调出一个参数，但我希望它从向量中获取：

    void WriteBucket(std::ifstream &input_file, uint64_t bucket_size, size_t bucket_number) {
    std::vector<double> numbers;
    for (size_t i = 0; i < bucket_size && input_file; ++i) {
        double current_number;
        input_file >> current_number;
        if (input_file) {
            numbers.push_back(current_number);
        }
    }

    sort(numbers.begin(), numbers.end());
    std::ofstream output_file("intermediate_output_" + std::to_string(bucket_number));
    for (double number: numbers) {
        output_file << number << std::endl;
    }
}

我试着把它从向量和类型T中提取出来，但是结果最终不起作用:是否有可能更好地将读取从"ifstream“转换成”向量“？

    template<typename T>
static void WriteBucket(vector<T> &data, uint64_t bucket_size, size_t bucket_number) {

    std::vector<T> numbers;
    //   for (auto i = 0; i < bucket_size && !data.empty(); ++i) {
    for (size_t i = 0; i < bucket_size; ++i) {
        T current_number;
        current_number = data[i];
        if (!data.empty()) {
            numbers.push_back(current_number);
        }
    }
    sort(numbers.begin(), numbers.end());
    std::ofstream zwischen_ausgabe("intermediate_output_" + std::to_string(bucket_number));
    for (auto i = 0; i < numbers.size() - 1; ++i) {
        zwischen_ausgabe << numbers[i] << std::endl;
    }

}

Answer 1

是的，您可以将numbers的声明和第一个for循环替换为：

std::vector<T> numbers = data; 
if ( bucket_size < data.size() ) 
    numbers.resize( bucket_size );

或

std::vector<T> numbers( data.begin(), data.begin() + std::min( data.size(), bucket_size ) );