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My compiler is Visual VC++ 2013. The following simplest program will cause a few memory leaks.
Why? How to fix it?
#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>
#include <cstdlib>
#include <iostream>
#include <locale>
using namespace std;
int main()
{
_CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF|_CRTDBG_LEAK_CHECK_DF);
cout.imbue(locale("")); // If this statement is commented, then OK.
}
The debug window outputs as follows:
Detected memory leaks!
Dumping objects ->
{387} normal block at 0x004FF8C8, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{379} normal block at 0x004FF678, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{352} normal block at 0x004FE6E8, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{344} normal block at 0x004FE498, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{318} normal block at 0x004FD5C8, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{308} normal block at 0x004F8860, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
Object dump complete.
Detected memory leaks!
Dumping objects ->
{387} normal block at 0x004FF8C8, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{379} normal block at 0x004FF678, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{352} normal block at 0x004FE6E8, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{344} normal block at 0x004FE498, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{318} normal block at 0x004FD5C8, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
{308} normal block at 0x004F8860, 12 bytes long.
Data: <z h - C N > 7A 00 68 00 2D 00 43 00 4E 00 00 00
Object dump complete.
The program '[0x5B44] cpptest.exe' has exited with code 0 (0x0).
608
Memory leaks occur when new memory is allocated dynamically and never deallocated. In C programs, new memory is allocated by the malloc or calloc functions, and deallocated by the free function. In C++, new memory is usually allocated by the new operator and deallocated by the delete or the delete [] operator.
In computer science, a memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in a way that memory which is no longer needed is not released. A memory leak may also happen when an object is stored in memory but cannot be accessed by the running code.
Memory leaks don't result in physical or permanent damage. Since it's a software issue, it will slow down the applications or even your whole system. However, a program taking up a lot of RAM space doesn't always mean its memory is leaking somewhere. The program you're using may really need that much space.
DEFINITION A memory leak is the gradual deterioration of system performance that occurs over time as the result of the fragmentation of a computer's RAM due to poorly designed or programmed applications that fail to free up memory segments when they are no longer needed.
I was using std::codecvt and get a similar problem. I am not sure whether it is a same cause. Just try to provide s possible way to discover the root cause.
You can reference the example in http://www.cplusplus.com/reference/locale/codecvt/in/
It actually "use" the member of mylocale, and it seems without an r-value reference version overload. So when directly write const facet_type& myfacet = std::use_facet<facet_type>(std::locale()); may cause the same problem. .
So try
auto myloc = locale("");
cout.imbue(myloc);
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