c++ - What's the purpose of having a separate "operator new[]"?

Question

Looks like operator new and operator new[] have exactly the same signature:

void* operator new( size_t size );
void* operator new[]( size_t size );

and do exactly the same: either return a pointer to a big enough block of raw (not initialized in any way) memory or throw an exception.

Also operator new is called internally when I create an object with new and operator new[] - when I create an array of objects with new[]. Still the above two special functions are called by C++ internally in exactly the same manner and I don't see how the two calls can have different meanings.

What's the purpose of having two different functions with exactly the same signatures and exactly the same behavior?

Answer 1

The operators can be overridden (for a specific class, or within a namespace, or globally), and this allows you to provide separate versions if you want to treat object allocations differently from array allocations. For example, you might want to allocate from different memory pools.