[c/c++]_[intermediate]_[Use smart pointers to release malloc out of Heap space]

Scene:

1. The Wrap class object can be wrapped using auto_ptr, then the object can be disposed automatically after the method ends, so that the free statement or CloseHandle can be omitted when a conditional-judged statement is available.

http://blog.csdn.net/infoworld/article/details/9008911

One of the attributes of 2.c++ is that the class object (an object that is not a return value) automatically calls the destructor at the end of the method, so that the destructor can be placed to release resources.

3. Here is a practical wrap class for a class similar to Auto_ptr, and you can refer to customizing the specific wrap class to your own needs. One of the drawbacks of auto_ptr is that it only supports new objects.

The second is that the array cannot be deleted. Delete []

4. Proper use of wrapobject can effectively reduce memory leaks, because in many C programming, too many if statements need to release objects before they return, making it easy to make mistakes or release multiple times.

File Wrap_object.h

#ifndef __wrap_object#define __wrap_object#include <stdlib.h> #include <windows.h>template<bool ( winapi* wraphandlefunc) (void*) >class wraphandle{public:wraphandle (void* data):d Ata_ (data) {}~wraphandle () {if ( Data_) {wraphandlefunc (data_);d ata_ = NULL;}} Private:void* Data_;}; Class Wrapmalloc{public:wrapmalloc (void* data):d Ata_ (data) {}~wrapmalloc () {free (data_);d ata_ = NULL;} void Reset () {free (data_);d ata_ = NULL;} Private:void* Data_;}; #endif

How to use:

Specify an HTTP server.  Const char* www = "www";  std::string urladdr = Dhoptiondomain::getvalue ("Url:brand");    Const char* Www_start = STRSTR (Urladdr.c_str (), www);  if (!hsession) {return knetworkerror;    } wraphandle<winhttpclosehandle> Session_wh (hsession);  wchar_t* Www_start_unicode = Convertutf8tounicode (Www_start);  Wrapmalloc WWW_WM (Www_start_unicode);   Hconnect = Winhttpconnect (hsession, Www_start_unicode, Internet_default_http_port, 0);    Create an HTTP request handle.    if (!hconnect) {return knetworkerror;  } wraphandle<winhttpclosehandle> Connect_wh (hconnect); Hrequest = Winhttpopenrequest (Hconnect, L "GET", L "/win-update.xml", NULL, Winhttp_no_ REFERER, Winhttp_default_accept_types, Winhttp_f   Lag_refresh);    Send a request.  if (!hrequest) {return knetworkerror; } WRAPHANDLE&LT;WINHTTPCLOsehandle> REQUEST_WH (hrequest);                                     Bresults = WinHttpSendRequest (hrequest, winhttp_no_additional_headers, 0,    Winhttp_no_request_data, 0, 0, 0);    End the request.  if (!bresults) {return knetworkerror;   } bresults = Winhttpreceiveresponse (hrequest, NULL);

Note: If you don't have wrapobject, you have to remember to release the ever-increasing handle object in the IF, which is one of the benefits of improving the quality of the program and is recommended to be used directly in the project.

[c/c++]_[intermediate]_[Use smart pointers to release malloc out of Heap space]