编辑“︁C++ 异步任务”︁（章节）

=== 并行计算 ===  
计算两个向量的点积，分解为多个异步任务：  
<syntaxhighlight lang="cpp">  
#include <vector>  
#include <numeric>  
#include <future>  

double dot_product(const std::vector<double>& a, const std::vector<double>& b, size_t start, size_t end) {  
    return std::inner_product(a.begin() + start, a.begin() + end, b.begin() + start, 0.0);  
}  

int main() {  
    std::vector<double> a(1000, 1.0), b(1000, 2.0);  
    auto fut1 = std::async(std::launch::async, dot_product, std::ref(a), std::ref(b), 0, 500);  
    auto fut2 = std::async(std::launch::async, dot_product, std::ref(a), std::ref(b), 500, 1000);  
    double result = fut1.get() + fut2.get();  
    std::cout << "Dot product: " << result << std::endl; // 输出 2000  
}  
</syntaxhighlight>