Convert a pointer to an array in C++

c++ arrays pointers memory-mapping
Zain Rizvi picture Zain Rizvi · Aug 21, 2009 · Viewed 18.6k times · Source

The CreateFileMapping function returns a pointer to a memory mapped file, and I want to treat that memory mapping as an array.

Here's what I basically want to do:

char Array[] = (char*) CreateFileMapping(...);

Except apparently I can't simply wave my arms and declare that a pointer is now an array.

Do you guys have any idea how I can do this? I don't want to copy the the values the pointer is pointing to into the array because that will use too much memory with large files.

Thanks a bunch,

Answer

Pavel Minaev picture Pavel Minaev · Aug 21, 2009

You do not need to. You can index a pointer as if it was an array:

char* p = (char*)CreateFileMapping(...);
p[123] = 'x';
...

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