Is the pointer guaranteed to be > a certain value?

Question

In C++ when i do new (or even malloc) is there any guarantee that the return address will be greater than a certain value? Because... in this project i find it

Answer 1

In terms of standard, there is nothing. But in reality, it depends on the target OS, windows for instance reserves the first 64kb of memory as a no-mans land (depending on the build it is read-only memory, else it is marked as PAGE_NOACCESS), while it uses the upper 0x80000000+ for kernel memory, but it can be changed, see this & this on MSDN.

On x64 you can also use the higher bits of the address (only 47bits are used for addresses currently), but its not such a good idea, as later on it will change and your program will break (AMD who set the standard also advise against it).