按值返回，请依赖 RVO（返回值优化）。

  auto make_big_vector（）
 {
 vector< huge_thing> v1; 
 //填充v1 

 //这里不需要显式移动
 return v1; 
} 

 auto make_big_stuff_tuple（）
 {
 vector< double> v0; 
 // fill v0 

 vector< huge_thing> v1; 
 // fill v1 

 // make_tuple的参数需要显式移动，
 //因为make_tuple使用了完美转发：
 // http：// en .cppreference.com / w / cpp / utility / tuple / make_tuple 

 return std :: make_tuple（std :: move（v0），std :: move（v1））; 
} 

 auto r0 = make_big_vector（）; 
 auto r1 = make_big_stuff_tuple（）; 
 

我会更改你的函数的API以简单地返回值。

I'm realy confused about returning large data in C++11. What is the most efficient way? Here is my related function:

void numericMethod1(vector<double>& solution,
                    const double input);

void numericMethod2(pair<vector<double>,vector<double>>& solution1,
                    vector<double>& solution2,
                    const double input1,
                    const double input2);

and here is the way i use them:

int main()
{
    // apply numericMethod1
    double input = 0;
    vector<double> solution;
    numericMethod1(solution, input);

    // apply numericMethod2
    double input1 = 1;
    double input2 = 2;
    pair<vector<double>,vector<double>> solution1;
    vector<double> solution2;
    numericMethod2(solution1, solution2, input1, input2);

    return 0;
}

The question is, is the std::move() useless in following implemtation?

Implementation:

void numericMethod1(vector<double>& solution,
                    const double input)
{
    vector<double> tmp_solution;

    for (...)
    {
    // some operation about tmp_solution
    // after that this vector become very large
    }

    solution = std::move(tmp_solution);
}

void numericMethod2(pair<vector<double>,vector<double>>& solution1,
                    vector<double>& solution2,
                    const double input1,
                    const double input2)
{
    vector<double> tmp_solution1_1;
    vector<double> tmp_solution1_2;
    vector<double> tmp_solution2;

    for (...)
    {
    // some operation about tmp_solution1_1, tmp_solution1_2 and tmp_solution2
    // after that the three vector become very large
    }

    solution1.first = std::move(tmp_solution1_1);
    solution1.second = std::move(tmp_solution1_2);
    solution2 = std::move(tmp_solution2);
}

If they are useless, how can i deal with these large return value without copy many times? Free to change the API!

UPDATE

Thanks to *** and these answers, after diving into related questions, I know this problem better. Due to RVO, I change the API, and for more clear, I don't use std::pair anymore. Here, is my new code:

struct SolutionType
{
    vector<double> X;
    vector<double> Y;
};

SolutionType newNumericMethod(const double input1,
                              const double input2);

int main()
{
    // apply newNumericMethod
    double input1 = 1;
    double input2 = 2;
    SolutionType solution = newNumericMethod(input1, input2);

    return 0;
}

SolutionType newNumericMethod(const double input1,
                              const double input2);
{
    SolutionType tmp_solution; // this will call the default constructor, right?
    // since the name is too long, i make alias.
    vector<double> &x = tmp_solution.X;
    vector<double> &y = tmp_solution.Y;

    for (...)
    {
    // some operation about x and y
    // after that these two vectors become very large
    }

    return tmp_solution;
}

How can I know RVO is happened? or How can I ensure RVO happened?

Return by value, rely on RVO (return value optimization).

auto make_big_vector()
{
    vector<huge_thing> v1;
    // fill v1

    // explicit move is not necessary here        
    return v1;
} 

auto make_big_stuff_tuple()
{
    vector<double> v0;
    // fill v0

    vector<huge_thing> v1;
    // fill v1

    // explicit move is necessary for make_tuple's arguments,
    // as make_tuple uses perfect-forwarding:
    // http://en.cppreference.com/w/cpp/utility/tuple/make_tuple

    return std::make_tuple(std::move(v0), std::move(v1));
}

auto r0 = make_big_vector();
auto r1 = make_big_stuff_tuple();

I would change the API of your functions to simply return by value.