2D的Wavefront如下图所示：

#include <taskflow/taskflow.hpp>


std::mutex cout_mutex;
void format_str(std::string const& str) {
    std::lock_guard<std::mutex> lock(cout_mutex); 
    std::cout << str << std::endl;
}

std::string createTaskName(int i, int j) {
    return "Task" + std::to_string(i) + "_" + std::to_string(j);
}
int main() {

    tf::Executor executor;
    tf::Taskflow taskflow;
    int num_blocks = 3; // 3*3的 Wavefront 
    std::vector<std::vector<tf::Task>>  Tasks(num_blocks); // 存放每个task对象

    for(int i = 0; i < num_blocks; i++) {
        for(int j = 0; j < num_blocks; j++) {
            const std::string task_name = createTaskName(i,j);

            // 创建task[i][j]
            Tasks[i].emplace_back(
                taskflow.emplace([task_name](){
                    format_str(task_name);
                }).name(task_name)
            );
            // 构建依赖关系
            if(i > 0) {
                Tasks[i][j].succeed(Tasks[i-1][j]);
            }
            if(j > 0) {
                Tasks[i][j].succeed(Tasks[i][j-1]);
            }
            
        }
    }

    executor.run(taskflow).wait();
    taskflow.dump(std::cout);
}