How to declare a cotaskmemfree

[Patrickboy]

I am working on old COM project. Here there is a file in the project which gives two function. The first on is allcoate memory and the second one is free memory. Nothing happen here when I call cotaskmemfree function. I do not understand weather I am doing right or wrong. Some one can please give steps to call the function.

[Reegan]

CoTaskMemFree Function is called to free some types of blocks in allocated memory. It clears up the memory related with a pointer to an itemidlist structure. This is created by windows shell api function. Once the function is called it does not return any value. You can get any simple example over the net. It shows you detail list of function to call and codes required.

[opaper]

It is mainly used to frees a block of task memory which is previously allocated. It is allocated when CoTaskMemAlloc and CoTaskMemRealloc function is called. See the example below.
The syntax below is used in C++ -

void CoTaskMemFree(
  __in_opt  LPVOID pv
);

Parameters required. -- pv [in, optional]. Here you will need a pointer to the memory block which require to be freed. If the parameter is null then you get no effect.

[MindSpace]

From the above reply you can understand the exact function and the way to call cotaskmemfree function. The number of bytes which he frees is equal to the number of bytes that were allocated. Then after the call the memory block pointed to by pv is not valid. It cannot be used any longer. A defualt OLE allocator is used by it. Any invalid function can result in unexpected crash of application.