添加#define new时,不是可识别的运算符或类型

Question

我正在尝试解决我的程序的一部分,它有一个#define new.一切都运行良好,直到我尝试创建一个覆盖新运算符的类模板,当我得到错误时:

C:\Define_New_problem\main.cpp:18: error: expected type-specifier before 'dPushMemManFileLine'
C:\Define_New_problem\main.cpp:18: error: expected ';' before 'dPushMemManFileLine'
C:\Define_New_problem\main.cpp:21: error: expected ';' before '}' token
Process terminated with status 1 (0 minutes, 0 seconds)

使用MinGW.(简化)代码如下:

#include <iostream>

#define new dPushMemManFileLine( __FILE__, __LINE__ ) ? 0 : new

using namespace std;

static const int NUM_NEW_STACK_SIZE = 256;
static struct { const char* filename; unsigned int line; } g_NewStackMemDebug[NUM_NEW_STACK_SIZE];
static int g_CurStack = -1;

template <class T>
class mypair {
  private:
    int a, b;
  public:
    mypair (int first, int second)
      {a=first; b=second;}
    static void* operator new(size_t size)
    {
    }
};

int dPushMemManFileLine( const char* filename, unsigned int line )
{
    if(g_CurStack >= NUM_NEW_STACK_SIZE )
        return 0;

    g_CurStack++;
    g_NewStackMemDebug[g_CurStack].filename = filename;
    g_NewStackMemDebug[g_CurStack].line = line;

    return 0; // needed for the new passthrough trick

}

int main()
{
    cout << "Hello world!" << endl;
    return 0;
}

有谁知道如何解决这个问题？

Answer 1

Don't.Ever.#define.关键词.

请不要.它只会产生问题.A #define将所定义单词的所有出现替换为您定义的单词,因此在#define'd new展开后,运算符重载如下所示:

static void* operator dPushMemManFileLine( __FILE__, __LINE__ ) ? 0 : new(size_t size)
    {
    }

Uuups ....
当然问题仍然存在,你为什么这样做？