c++ - 结构成员字段是函数指针时出错

Question

我需要让 struct member 成为常规函数指针(而不是类成员函数指针)。不知道为什么编译错误。我在 Ubuntu 14.04 上运行 g++ 4.8.4。谢谢。

$ g++ te5.cc
te5.cc: In function ‘int main(int, char**)’:
te5.cc:18:9: error: invalid use of member function (did you forget the ‘()’ ?)
  t.func = dum;
         ^
te5.cc:19:6: error: ‘func’ was not declared in this scope
  (t.*func)();

代码片段

#include <stdio.h>
#include <string>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef void pfpv(void *obj);
typedef struct {
    pfpv  func;
    void *obj;
} strTimer;

void dum(void* p) {
    printf("in dum()\n");
}

int main (int argc, char *argv[]) {
    strTimer t;
    t.func = dum;
    (t.*func)();
    return 0;
}

Answer 1

这可以通过使 pfpv 成为函数指针而不是函数来解决。

#include <stdio.h>
#include <string>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef void (*pfpv)(void *obj);

typedef struct {
    pfpv  func;
    void *obj;
} strTimer;

void dum(void* p) {
    printf("in dum()\n");
}

int main (int argc, char *argv[]) {
    strTimer t;
    t.func = dum;
    t.func(0);
    return 0;
}