Probably simple question about freeing dynamic variables

[bigsofty]

Hi,

I have a struct...

struct Vertex
{
	short v[2];
};

struct VertexInfo
{
	Vertex* vertex;
	int _vertexCount;
};

I create an instance of Vertex info within a function and save the pointer in a global(batch).

VertexInfo* batch = new VertexInfo;

Now here is my question...

When I allocate a dynamic array in batch->vertex and at a later point delete batch, does that mean that the array(within batch) 'vertex' is freed also(since its a child of batch)?

Or do I have to delete vertex first, then delete batch?

Many thanks for any advice,


Softy.

[IceThatJaw]

You have to delete vertex first, then batch. C++ does not handle your deletes so whenever you declare space of the heap, you better delete it somewhere, no matter how deep the allocation is in your structures.

[bigsofty]

So, even though VertexInfo has been put on the heap, I have to iterate any pointers within VertexInfo that have been allocated memory too? I assumed that if a parent on the heap gets deleted, then all child structures would too? I think I may be expecting too much from the heap manager.

Please excuse me for reiterating my question as I am trying to clear it up in my own head.


Softy.

[IceThatJaw]

Nah, it's not that easy in C++. There is ZERO garbage cleanup. Every single bit of memory you allocate in the heap needs to be explicitly deleted somewhere.

[Cubbi]

If you're serious about learning C++, stop using 'new' unnecessarily:

#include <vector>
struct Vertex
{
    short v[2];
};
struct VertexInfo
{
    std::vector<Vertex> vertex;
    VertexInfo(std::size_t initial_size) : vertex(initial_size) {}
};

int main()
{
    VertexInfo batch(10);
} // batch is deleted, and every vertex is deleted as well. 

[bigsofty]

Very clear now IceThatJaw, thank you. :)

@Cubbi:
I am restricted to dynamic data structures due to a restriction of the problem I am trying to solve with inline c++ using GLBasic.

I must say that I am enjoying learning c++ more than I expected.

Thanks again for all you help guys!


Softy.