C++函数中，两个自动释放内存的动态内存申请类
最近做一个事情，实现一个流程交互，其中主交互流程函数中，涉及较多的内存申请，

而健康的函数，都是在函数退出前将手动申请不再需要的内存释放掉，

使用很多方法，都避免不了较多的出错分支时，一堆的if free/delete，代码长而且不好管理

因此，利用C++对象离开作用域会自动调用析构函数的特点，在这儿实现了两个自动释放内存的动态内存申请类

第一个类，只管理内存，不并管理对象

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include

class XAutoFreeMem
{
protected:

std::vector<void*> vec_memorys_;

public:

XAutoFreeMem::XAutoFreeMem() {};virtual XAutoFreeMem::~XAutoFreeMem(){    //释放对象时，释放管理的内存    for(auto item : vec_memorys_){        free(item);    }}//通过此接口来申请内存void* malloc_mem(unsigned int nsize) {    void* ptr = malloc(nsize);    if (nullptr != ptr) {        vec_memorys_.push_back(ptr);    }    return ptr;}

};
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第二个类，能够同时支持内存管理、对象管理

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typedef void (delete_obj_func)(void);

class XAutoFree : public XAutoFreeMem
{
private:

typedef struct  _manager_st{    void* obj_this;    delete_obj_func delete_ptr;} _manager_st;

protected:

template<typename T>static void free_ (T* p_this){    delete p_this;}template<typename T>static void free_ s(T* p_this){    delete []p_this;}

protected:

std::vector< _manager_st> vec_ s_;

public:

XAutoFree ::XAutoFree () {};virtual XAutoFree ::~XAutoFree (){    //释放对象时，释放管理的对象    for(auto item : vec_ s_){        (*item.delete_ptr)(item.obj_this);    }}//对象//通过此接口来创建对象template<typename T>void new_ (T** ppObj) {     _manager_st stObjMan;    stObjMan.obj_this = new T;    if (nullptr != stObjMan.obj_this) {        //取得函数指针        stObjMan.delete_ptr =(delete_obj_func) & free_ <T>;        //保存之        vec_ s_.push_back(stObjMan);    }    *ppObj = (T*)(stObjMan.obj_this);    return;}//通过此接口来创建对象template<typename T, typename P>void new_ _with_param(T** ppObj, P param){     _manager_st stObjMan;    stObjMan.obj_this = new T(param);    if (nullptr != stObjMan.obj_this) {        //取得函数指针        stObjMan.delete_ptr = & free_ <T>;        //保存之        vec_ s_.push_back(stObjMan);    }    *ppObj = (T*)(stObjMan.obj_this);    return;}//通过此接口来创建对象，这几个接口使用会麻烦一些，使用示例：std::string* pstr = stAutoManager.new_ <std::string> ();template<typename T>T* new_ () {     _manager_st stObjMan;    stObjMan.obj_this = new T;    if (nullptr != stObjMan.obj_this) {        //取得函数指针        stObjMan.delete_ptr =(delete_obj_func) & free_ <T>;        //保存之        vec_ s_.push_back(stObjMan);    }    return (T*)(stObjMan.obj_this);}//通过此接口来创建对象template<typename T, typename P>T* new_ _with_param(P param){     _manager_st stObjMan;    stObjMan.obj_this = new T(param);    if (nullptr != stObjMan.obj_this) {        //取得函数指针        stObjMan.delete_ptr = & free_ <T>;        //保存之        vec_ s_.push_back(stObjMan);    }    return (T*)(stObjMan.obj_this);}//对象数组//通过此接口来创建对象数组template<typename T>void new_ s(T** ppObj, int num) {     _manager_st stObjMan;    stObjMan.obj_this = new T[num];    if (nullptr != stObjMan.obj_this) {        //取得函数指针        stObjMan.delete_ptr =(delete_obj_func) & free_ s<T>;        //保存之        vec_ s_.push_back(stObjMan);    }    *ppObj = (T*)(stObjMan.obj_this);    return;}//通过此接口来创建对象数组template<typename T, typename P>void new_ s_with_param(T** ppObj, int num, P param){     _manager_st stObjMan;    stObjMan.obj_this = new T[num](param);    if (nullptr != stObjMan.obj_this) {        //取得函数指针        stObjMan.delete_ptr = & free_ <T>;        //保存之        vec_ s_.push_back(stObjMan);    }    *ppObj = (T*)(stObjMan.obj_this);    return;}//通过此接口来创建对象数组template<typename T>T* new_ s(int num) {     _manager_st stObjMan;    stObjMan.obj_this = new T[num];    if (nullptr != stObjMan.obj_this) {        //取得函数指针        stObjMan.delete_ptr =(delete_obj_func) & free_ <T>;        //保存之        vec_ s_.push_back(stObjMan);    }    return (T*)(stObjMan.obj_this);}//通过此接口来创建对象数组template<typename T, typename P>T* new_ s_with_param(int num, P param){     _manager_st stObjMan;    stObjMan.obj_this = new T[num](param);    if (nullptr != stObjMan.obj_this) {        //取得函数指针        stObjMan.delete_ptr = & free_ <T>;        //保存之        vec_ s_.push_back(stObjMan);    }    return (T*)(stObjMan.obj_this);}

};
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调用示例如下：

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int main(int argc, char* argv[])
{

//cwSL3D_test_sum();//测试能否成功调用所有接口XAutoFree  stAutoManager;char* strMem = (char*)stAutoManager.malloc_mem(100);std::string* pstr = stAutoManager.new_ <std::string> ();std::string* pstr2 = nullptr;stAutoManager.new_ (&pstr2);{    std::vector<int>* pvec = nullptr;    stAutoManager.new_ (&pvec);    std::vector<int>* pvec2 = nullptr;    stAutoManager.new_ s(&pvec, 2);}return 0;

}
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原文地址https://www.cnblogs.com/eaglexmw/p/11405424.html