C++ 模仿sizeof

    可以使用C的宏和C++模板加上数组，模拟sizeof操作符。如果有浮点数或者class中的private数值等，只能不觉明历了。
Example:

// implement_sizeof.cpp
//
#include <iostream>

using namespace std;

#define SIZEOF(x) ((char *)(&x+1) - (char *)(&x));

template <typename T>
unsigned long int SIZEOF_CPP(const T &v)
{
    return (char *)(&v+1) - (char *)(&v);
}

template <unsigned long int N >
unsigned long int SIZEOF_CPP_SEC(char (*t)[N])
{
    return N;
};

template <typename T, unsigned long int N >
unsigned long int SIZEOF_CPP_ARRAY(T (&t)[N])
{
    return N;
};

typedef struct _SizeofTest
{
    int _size1;
    int _size2;
    char _size3;
}SizeofTest;

int main(int argc, char* argv[])
{
    SizeofTest data = {0};
    SizeofTest dataArray[10] = {0};
    unsigned long int size_c = SIZEOF(data);
    unsigned long int size_cpp = SIZEOF_CPP(data);
    unsigned long int size_cpp_array = SIZEOF_CPP_ARRAY(dataArray);
    cout<<"size_c ="<<size_c <<endl
        <<"size_cpp ="<<size_cpp <<endl
        <<"size_cpp_array ="<<size_cpp_array <<endl;

    const int x = 63;
    typedef int (*newDefine[x]);
    typedef int newDefine_sec[x];
    typedef int (*newDefine_third)[x];

    int ** pp = new (int (*[x]));
    int size_new = sizeof(newDefine);
    int size_new_sec = sizeof(newDefine_sec);
    int size_new_third = sizeof(newDefine_third);
    cout<<"size_new =" <<size_new <<endl
        <<"size_new_sec =" <<size_new_sec <<endl
        <<"size_new_third ="<<size_new_third <<endl;

    return 0;
}

Result：

size_c =12
size_cpp =12
size_cpp_array =10
size_new =252
size_new_sec =252
size_new_third =4