Overloading operator new

I am overloading operator new as below

class A {
public:
    void* operator new(size_t) { return (void*) Buf; }
};

I am getting "declaration of opera开发者_如何学运维tor new as non-function error" when I try to compile. Could someone help me with this?

Have you size_t be defined? You need to include stddef.h for it. But better you include cstddef and use std::size_t.

Your declaration otherwise looks fine, apart from the semantics of always returning Buf being screwed up. The operator new should return a buffer of the size specified as the first argument.

I'm guessing that you are using a fairly modern and strict compiler. The error you are getting is because size_t is not recognized. Strictly you need to #include something that defines it and you should also use the C++ name: std::size_t.

E.g.

#include <cstddef>

class A{
public:
void* operator new(std::size_t) { return (void*) Buf;}
};