网站新闻稿模板,接外包网站,外包+网站开发公司,做网站的主题有哪些unique_ptr大小和删除器有很大关系#xff0c;具体区别看如下代码的分析。不要让unique_ptr占用的空间太大#xff0c;否则不会达到裸指针同样的效果。
#include iostream
#include memory
using namespace std;class Widget {int m_x;int m_y;int m_z;publ…unique_ptr大小和删除器有很大关系具体区别看如下代码的分析。不要让unique_ptr占用的空间太大否则不会达到裸指针同样的效果。
#include iostream
#include memory
using namespace std;class Widget {int m_x;int m_y;int m_z;public:Widget(int x, int y, int z) :m_x(x), m_y(y), m_z(z){}void print() {cout m_x , m_y , m_z endl;}~Widget(){cout Widget dtor endl;}
};struct DeleteWithLog {void operator()(Widget* w) {data;delete w;cout ------ DeleteWithLog delete w endl;}int data;
};void deleteFunction(Widget* w) {delete w;cout ------ deleteFunction delete w endl;
}int main()
{{unique_ptrWidget w1(new Widget(1, 2, 3));w1-print();cout sizeof(w1) sizeof(w1) endl;cout ------ default delete endl;}{DeleteWithLog dw;unique_ptrWidget, DeleteWithLog w2(new Widget(10, 20, 30));w2-print();cout sizeof(w2) sizeof(w2) endl;}int data1, data2, data3;{auto lambda [](Widget * w) {cout data1 data2 data3 endl;delete w;cout ------ lambda delete w endl;};unique_ptrWidget, decltype(lambda) w3(new Widget(100, 200, 300), lambda);w3-print();cout sizeof(w3) sizeof(w3) endl;}{unique_ptrWidget, void(*)(Widget*)w4(new Widget(1000, 2000, 3000), deleteFunction);w4-print();cout sizeof(w4) sizeof(w4) endl;}system(pause);
}结果
