auto action_server = std::make_shared<ActionRobot01>("action_robot_01"); rclcpp::spin(action_server); rclcpp::shutdown(); return 0; } 1.5 action_control_01.cpp #include "rclcpp/rclcpp.hpp" #include "rclcpp_action/rclcpp_action.hpp" #include "robot_control_interfaces/action/move_robot.h...
http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#discussion-use-a-factory-function-if-you-need-virtual-behavior-during-initialization uses std::make_shared() to construct shared pointer to derived class. I think std::make_shared() cannot be used here since the constructor of the ...
无持有者!!"<<std::endl;}elseif((bool)ptr!=0){std::cout<<"所有权计数为"<<ptr.use_count()<<std::endl;}}intmain(){std::shared_ptr<int>ptr_one;Print_Owner(ptr_one);//0ptr_one=std::make_shared<int>(100);/
45Writer::WriteCallbackFunc cb) {46auto varint_len = multi::UVarint{static_cast<uint64_t>(buffer.size())};4748auto msg_bytes = std::make_shared<std::vector<uint8_t>>();49msg_bytes->reserve(varint_len.size() +buffer.size());50msg_bytes->insert(msg_bytes->end(),51std::make_...
类似std::make_shared,此函数通常只进行一次分配,并将T对象与控制块都置于分配的内存块中(标准推荐但不要求如此,所有已知实现均如此)。alloc的一个副本作为控制块的一部分存储,从而当所有共享及若引用计数抵达零时能用于它的解分配。 不同于std::shared_ptr构造函数,std::allocate_shared不接受另外的自定义删除器...
std::make_shared memory model std::async C++17 Language Features Template argument deduction for class templates Automatic template argument deduction much like how it's done for functions, but now including class constructors. template <typename T = float> struct MyContainer { T val; MyContainer...
shared_ptr能够记录多少个shared_ptr共同指向一个对象,从而消除显式调用delete,当引用计数变为零的时候就会将对象自动删除。 注意,这里使用shared_ptr能够实现自动delete,但是如果使用之前仍需要new的话,代码风格就会变得很「奇怪」,因为new/delete总是需要成对出现的,所以尽可能使用封装后的make_shared来「代替」new。
std::shared_ptr是一种通过指针保持对象共享所有权的智能指针。多个shared_ptr对象可持有同一对象。下列情况之一出现时销毁对象并解分配其内存: 最后剩下的持有对象的shared_ptr被销毁; 最后剩下的持有对象的shared_ptr被通过operator=或reset()赋值为另一指针。
g_chn = std::make_shared<hisilicon::dev::chn>(g_vi_info[chn].name,g_venc_info[chn].name,chn); g_chn->start(g_venc_info[chn].w,g_venc_info[chn].h,g_venc_info[chn].fr,g_venc_info[chn].bitrate); hisilicon::dev::chn::start_capture(true); //scene get_scene_info()...
#include <iostream>#include <memory>intmain(){autosp1=std::make_shared<int>(5);std::cout<<std::boolalpha;std::cout<<"sp1.unique() == "<<sp1.unique()<<'\n';std::shared_ptr<int>sp2=sp1;std::cout<<"sp1.unique() == "<<sp1.unique()<<'\n';} ...