使用C语言实现vector动态数组的实例分享

所属分类: 软件编程 / C 语言 阅读数: 74
收藏 0 赞 0 分享

下面是做项目时实现的一个动态数组,先后加入了好几个之后的项目,下面晒下代码。

头文件:

# ifndef __CVECTOR_H__ 
# define __CVECTOR_H__ 
# define MIN_LEN 256 
# define CVEFAILED -1 
# define CVESUCCESS 0 
# define CVEPUSHBACK 1 
# define CVEPOPBACK 2 
# define CVEINSERT  3 
# define CVERM    4 
# define EXPANED_VAL 1 
# define REDUSED_VAL 2 
 
typedef void *citerator; 
typedef struct _cvector *cvector; 
 
# ifdef _cplusplus 
# define EXTERN_ extern "C" 
# else 
# define EXTERN_ extern 
# endif 
 
EXTERN_ cvector  cvector_create  (const size_t size              ); 
EXTERN_ void   cvector_destroy (const cvector cv              ); 
EXTERN_ size_t  cvector_length  (const cvector cv              ); 
EXTERN_ int    cvector_pushback (const cvector cv, void *memb        ); 
EXTERN_ int    cvector_popback (const cvector cv, void *memb        ); 
EXTERN_ size_t  cvector_iter_at (const cvector cv, citerator iter      ); 
EXTERN_ int    cvector_iter_val (const cvector cv, citerator iter, void *memb); 
EXTERN_ citerator cvector_begin  (const cvector cv              ); 
EXTERN_ citerator cvector_end   (const cvector cv              ); 
EXTERN_ citerator cvector_next   (const cvector cv, citerator iter      ); 
EXTERN_ int    cvector_val_at  (const cvector cv, size_t index, void *memb ); 
EXTERN_ int    cvector_insert  (const cvector cv, citerator iter, void *memb); 
EXTERN_ int    cvector_insert_at(const cvector cv, size_t index, void *memb ); 
EXTERN_ int    cvector_rm    (const cvector cv, citerator iter      ); 
EXTERN_ int    cvector_rm_at  (const cvector cv, size_t index       );  
 
/* for test */ 
EXTERN_ void   cv_info     (const cvector cv              ); 
EXTERN_ void   cv_print     (const cvector cv              ); 
#endif /* EOF file cvector.h */ 


C文件:

# include <stdio.h> 
# include <stdlib.h> 
# include <string.h> 
# include <unistd.h> 
# define MIN_LEN 256 
# define CVEFAILED -1 
# define CVESUCCESS 0 
# define CVEPUSHBACK 1 
# define CVEPOPBACK 2 
# define CVEINSERT  3 
# define CVERM    4 
# define EXPANED_VAL 1 
# define REDUSED_VAL 2 
 
typedef void *citerator; 
typedef struct _cvector  
{    
  void *cv_pdata; 
  size_t cv_len, cv_tot_len, cv_size; 
} *cvector; 
 
# define CWARNING_ITER(cv, iter, file, func, line) \ 
  do {\ 
    if ((cvector_begin(cv) > iter) || (cvector_end(cv) <= iter)) {\ 
      fprintf(stderr, "var(" #iter ") warng out of range, "\ 
          "at file:%s func:%s line:%d!!/n", file, func, line);\ 
      return CVEFAILED;\ 
    }\ 
  } while (0) 
 
# ifdef _cplusplus 
# define EXTERN_ extern "C" 
# else 
# define EXTERN_ extern 
# endif 
 
EXTERN_ cvector  cvector_create  (const size_t size              ); 
EXTERN_ void   cvector_destroy (const cvector cv              ); 
EXTERN_ size_t  cvector_length  (const cvector cv              ); 
EXTERN_ int    cvector_pushback (const cvector cv, void *memb        ); 
EXTERN_ int    cvector_popback (const cvector cv, void *memb        ); 
EXTERN_ size_t  cvector_iter_at (const cvector cv, citerator iter      ); 
EXTERN_ int    cvector_iter_val (const cvector cv, citerator iter, void *memb); 
EXTERN_ citerator cvector_begin  (const cvector cv              ); 
EXTERN_ citerator cvector_end   (const cvector cv              ); 
EXTERN_ citerator cvector_next   (const cvector cv, citerator iter      ); 
EXTERN_ int    cvector_val_at  (const cvector cv, size_t index, void *memb ); 
EXTERN_ int    cvector_insert  (const cvector cv, citerator iter, void *memb); 
EXTERN_ int    cvector_insert_at(const cvector cv, size_t index, void *memb ); 
EXTERN_ int    cvector_rm    (const cvector cv, citerator iter      ); 
EXTERN_ int    cvector_rm_at  (const cvector cv, size_t index       ); 
 
/* for test */ 
EXTERN_ void   cv_info     (const cvector cv              ); 
EXTERN_ void   cv_print     (const cvector cv              ); 
 
cvector cvector_create(const size_t size) 
{ 
  cvector cv = (cvector)malloc(sizeof (struct _cvector)); 
 
  if (!cv) return NULL; 
 
  cv->cv_pdata = malloc(MIN_LEN * size); 
 
  if (!cv->cv_pdata)  
  { 
    free(cv); 
    return NULL; 
  } 
 
  cv->cv_size = size; 
  cv->cv_tot_len = MIN_LEN; 
  cv->cv_len = 0; 
 
  return cv; 
} 
 
void cvector_destroy(const cvector cv) 
{ 
  free(cv->cv_pdata); 
  free(cv); 
  return; 
} 
 
size_t cvector_length(const cvector cv) 
{ 
  return cv->cv_len; 
} 
 
int cvector_pushback(const cvector cv, void *memb) 
{ 
  if (cv->cv_len >= cv->cv_tot_len)  
  { 
    void *pd_sav = cv->cv_pdata; 
    cv->cv_tot_len <<= EXPANED_VAL; 
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size); 
 
    if (!cv->cv_pdata)  
    { 
      cv->cv_pdata = pd_sav; 
      cv->cv_tot_len >>= EXPANED_VAL; 
      return CVEPUSHBACK; 
    } 
  } 
 
  memcpy(cv->cv_pdata + cv->cv_len * cv->cv_size, memb, cv->cv_size); 
  cv->cv_len++; 
 
  return CVESUCCESS; 
} 
 
int cvector_popback(const cvector cv, void *memb) 
{ 
  if (cv->cv_len <= 0) return CVEPOPBACK; 
 
  cv->cv_len--; 
  memcpy(memb, cv->cv_pdata + cv->cv_len * cv->cv_size, cv->cv_size); 
 
  if ((cv->cv_tot_len >= (MIN_LEN << REDUSED_VAL))  
      && (cv->cv_len <= (cv->cv_tot_len >> REDUSED_VAL)))  
  { 
    void *pd_sav = cv->cv_pdata; 
    cv->cv_tot_len >>= EXPANED_VAL; 
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size); 
 
    if (!cv->cv_pdata)  
    { 
      cv->cv_tot_len <<= EXPANED_VAL; 
      cv->cv_pdata = pd_sav; 
      return CVEPOPBACK; 
    } 
  } 
 
  return CVESUCCESS; 
} 
 
size_t cvector_iter_at(const cvector cv, citerator iter) 
{ 
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__); 
  return (iter - cv->cv_pdata) / cv->cv_size; 
} 
 
int cvector_iter_val(const cvector cv, citerator iter, void *memb) 
{ 
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__); 
  memcpy(memb, iter, cv->cv_size); 
  return 0; 
} 
 
citerator cvector_begin(const cvector cv) 
{ 
  return cv->cv_pdata; 
} 
 
citerator cvector_end(const cvector cv) 
{ 
  return cv->cv_pdata + (cv->cv_size * cv->cv_len); 
} 
 
static inline void cvmemove_foreward(const cvector cv, void *from, void *to) 
{ 
  size_t size = cv->cv_size; 
  void *p; 
  for (p = to; p >= from; p -= size) memcpy(p + size, p, size); 
  return; 
} 
 
static inline void cvmemove_backward(const cvector cv, void *from, void *to) 
{ 
  memcpy(from, from + cv->cv_size, to - from); 
  return; 
} 
 
int cvector_insert(const cvector cv, citerator iter, void *memb) 
{ 
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__); 
 
  if (cv->cv_len >= cv->cv_tot_len)  
  { 
    void *pd_sav = cv->cv_pdata; 
    cv->cv_tot_len <<= EXPANED_VAL; 
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size); 
 
    if (!cv->cv_pdata)  
    { 
      cv->cv_pdata = pd_sav; 
      cv->cv_tot_len >>= EXPANED_VAL; 
      return CVEINSERT; 
    } 
  } 
 
  cvmemove_foreward(cv, iter, cv->cv_pdata + cv->cv_len * cv->cv_size); 
  memcpy(iter, memb, cv->cv_size); 
  cv->cv_len++; 
 
  return CVESUCCESS; 
} 
 
int cvector_insert_at(const cvector cv, size_t index, void *memb) 
{ 
  citerator iter; 
 
  if (index >= cv->cv_tot_len)  
  { 
    cv->cv_len = index + 1; 
    while (cv->cv_len >= cv->cv_tot_len) cv->cv_tot_len <<= EXPANED_VAL; 
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size); 
    iter = cv->cv_pdata + cv->cv_size * index; 
    memcpy(iter, memb, cv->cv_size); 
  } 
  else  
  { 
    iter = cv->cv_pdata + cv->cv_size * index; 
    cvector_insert(cv, iter, memb); 
  } 
 
  return 0; 
} 
 
citerator cvector_next(const cvector cv, citerator iter) 
{ 
  return iter + cv->cv_size; 
} 
 
int cvector_val(const cvector cv, citerator iter, void *memb) 
{ 
  memcpy(memb, iter, cv->cv_size); 
  return 0; 
} 
 
int cvector_val_at(const cvector cv, size_t index, void *memb) 
{ 
  memcpy(memb, cv->cv_pdata + index * cv->cv_size, cv->cv_size); 
  return 0; 
} 
 
int cvector_rm(const cvector cv, citerator iter) 
{ 
  citerator from; 
  citerator end; 
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__); 
  from = iter; 
  end = cvector_end(cv); 
  memcpy(from, from + cv->cv_size, end - from); 
  cv->cv_len--; 
 
  if ((cv->cv_tot_len >= (MIN_LEN << REDUSED_VAL)) 
      && (cv->cv_len <= (cv->cv_tot_len >> REDUSED_VAL)))  
  { 
    void *pd_sav = cv->cv_pdata; 
    cv->cv_tot_len >>= EXPANED_VAL; 
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size); 
 
    if (!cv->cv_pdata)  
    { 
      cv->cv_tot_len <<= EXPANED_VAL; 
      cv->cv_pdata = pd_sav; 
      return CVERM; 
    } 
  } 
 
  return CVESUCCESS; 
} 
 
int cvector_rm_at(const cvector cv, size_t index) 
{ 
  citerator iter; 
  iter = cv->cv_pdata + cv->cv_size * index; 
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__); 
  return cvector_rm(cv, iter); 
} 
 
void cv_info(const cvector cv) 
{ 
  printf("/n/ntot :%s : %d/n", __func__, cv->cv_tot_len); 
  printf("len :%s : %d/n",   __func__, cv->cv_len); 
  printf("size:%s : %d/n/n",  __func__, cv->cv_size); 
  return; 
} 
 
void cv_print(const cvector cv) 
{ 
  int num; 
  citerator iter; 
 
  if (cvector_length(cv) == 0) 
    fprintf(stderr, "file:%s func:%s line:%d error, null length cvector!!/n", __FILE__, __func__, __LINE__); 
 
  for (iter = cvector_begin(cv);  
      iter != cvector_end(cv); 
      iter = cvector_next(cv, iter))  
  { 
    cvector_iter_val(cv, iter, &num); 
    printf("var:%d at:%d/n", num, cvector_iter_at(cv, iter)); 
  } 
 
  return; 
} 

改进版
上面那份代码是在Linux下写的,如果是在Windows的Visul C++环境下编译似乎会出些问题,所以特别做了个改进版:
下面是更新后的代码:

cvector.h

# ifndef __CVECTOR_H__ 
# define __CVECTOR_H__ 
 
# include <stdio.h>  
# include <stdlib.h>  
# include <string.h>  
 
# define MIN_LEN 256 
# define CVEFAILED -1 
# define CVESUCCESS 0 
# define CVEPUSHBACK 1 
# define CVEPOPBACK 2 
# define CVEINSERT  3 
# define CVERM    4 
# define EXPANED_VAL 1 
# define REDUSED_VAL 2 
 
typedef void *citerator; 
typedef struct _cvector *cvector; 
 
# ifdef __cplusplus 
extern "C" { 
# endif 
 
  cvector  cvector_create  (const size_t size              ); 
  void   cvector_destroy (const cvector cv              ); 
  size_t  cvector_length  (const cvector cv              ); 
  int    cvector_pushback (const cvector cv, void *memb        ); 
  int    cvector_popback (const cvector cv, void *memb        ); 
  size_t  cvector_iter_at (const cvector cv, citerator iter      ); 
  int    cvector_iter_val (const cvector cv, citerator iter, void *memb); 
  citerator cvector_begin  (const cvector cv              ); 
  citerator cvector_end   (const cvector cv              ); 
  citerator cvector_next   (const cvector cv, citerator iter      ); 
  int    cvector_val_at  (const cvector cv, size_t index, void *memb ); 
  int    cvector_insert  (const cvector cv, citerator iter, void *memb); 
  int    cvector_insert_at(const cvector cv, size_t index, void *memb ); 
  int    cvector_rm    (const cvector cv, citerator iter      ); 
  int    cvector_rm_at  (const cvector cv, size_t index       ); 
 
  /* for test */ 
  void   cv_info     (const cvector cv              ); 
  void   cv_print     (const cvector cv              ); 
 
# ifdef __cplusplus 
} 
# endif 
 
#endif /* EOF file cvector.h */ 

cvector.c

#include "cvector.h" 
 
#ifndef __gnu_linux__ 
#define __func__ "unknown" 
#define inline __forceinline 
#endif 
 
# define CWARNING_ITER(cv, iter, file, func, line) \ 
  do {\ 
  if ((cvector_begin(cv) > iter) || (cvector_end(cv) <= iter)) {\ 
  fprintf(stderr, "var(" #iter ") warng out of range, "\ 
  "at file:%s func:%s line:%d!!\n", file, func, line);\ 
  return CVEFAILED;\ 
  }\ 
  } while (0) 
 
struct _cvector 
{ 
  void *cv_pdata; 
  size_t cv_len, cv_tot_len, cv_size; 
}; 
 
cvector cvector_create(const size_t size) 
{ 
  cvector cv = (cvector)malloc(sizeof (struct _cvector)); 
 
  if (!cv) return NULL; 
 
  cv->cv_pdata = malloc(MIN_LEN * size); 
 
  if (!cv->cv_pdata) 
  { 
    free(cv); 
    return NULL; 
  } 
 
  cv->cv_size = size; 
  cv->cv_tot_len = MIN_LEN; 
  cv->cv_len = 0; 
 
  return cv; 
}  
 
void cvector_destroy(const cvector cv)  
{  
  free(cv->cv_pdata);  
  free(cv);  
  return;  
}  
 
size_t cvector_length(const cvector cv)  
{  
  return cv->cv_len;  
}  
 
int cvector_pushback(const cvector cv, void *memb)  
{  
  if (cv->cv_len >= cv->cv_tot_len)   
  {  
    void *pd_sav = cv->cv_pdata;  
    cv->cv_tot_len <<= EXPANED_VAL;  
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size);  
 
    if (!cv->cv_pdata)   
    {  
      cv->cv_pdata = pd_sav;  
      cv->cv_tot_len >>= EXPANED_VAL;  
      return CVEPUSHBACK;  
    }  
  }  
 
  memcpy((char *)cv->cv_pdata + cv->cv_len * cv->cv_size, memb, cv->cv_size);  
  cv->cv_len++;  
 
  return CVESUCCESS;  
}  
 
int cvector_popback(const cvector cv, void *memb)  
{  
  if (cv->cv_len <= 0) return CVEPOPBACK;  
 
  cv->cv_len--;  
  memcpy(memb, (char *)cv->cv_pdata + cv->cv_len * cv->cv_size, cv->cv_size);  
 
  if ((cv->cv_tot_len >= (MIN_LEN << REDUSED_VAL))   
    && (cv->cv_len <= (cv->cv_tot_len >> REDUSED_VAL)))   
  {  
    void *pd_sav = cv->cv_pdata;  
    cv->cv_tot_len >>= EXPANED_VAL;  
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size);  
 
    if (!cv->cv_pdata)   
    {  
      cv->cv_tot_len <<= EXPANED_VAL;  
      cv->cv_pdata = pd_sav;  
      return CVEPOPBACK;  
    }  
  }  
 
  return CVESUCCESS;  
}  
 
size_t cvector_iter_at(const cvector cv, citerator iter)  
{  
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__);  
  return ((char *)iter - (char *)cv->cv_pdata) / cv->cv_size;  
}  
 
int cvector_iter_val(const cvector cv, citerator iter, void *memb)  
{  
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__);  
  memcpy(memb, iter, cv->cv_size);  
  return 0;  
}  
 
citerator cvector_begin(const cvector cv)  
{  
  return cv->cv_pdata;  
}  
 
citerator cvector_end(const cvector cv)  
{  
  return (char *)cv->cv_pdata + (cv->cv_size * cv->cv_len);  
}  
 
static inline void cvmemove_foreward(const cvector cv, void *from, void *to)  
{  
  size_t size = cv->cv_size;  
  char *p;  
  for (p = (char *)to; p >= (char *)from; p -= size) memcpy(p + size, p, size);  
  return;  
}  
 
static inline void cvmemove_backward(const cvector cv, void *from, void *to)  
{  
  memcpy(from, (char *)from + cv->cv_size, (char *)to - (char *)from);  
  return;  
}  
 
int cvector_insert(const cvector cv, citerator iter, void *memb)  
{  
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__);  
 
  if (cv->cv_len >= cv->cv_tot_len)   
  {  
    void *pd_sav = cv->cv_pdata;  
    cv->cv_tot_len <<= EXPANED_VAL;  
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size);  
 
    if (!cv->cv_pdata)   
    {  
      cv->cv_pdata = pd_sav;  
      cv->cv_tot_len >>= EXPANED_VAL;  
      return CVEINSERT;  
    }  
  }  
 
  cvmemove_foreward(cv, iter, (char *)cv->cv_pdata + cv->cv_len * cv->cv_size);  
  memcpy(iter, memb, cv->cv_size);  
  cv->cv_len++;  
 
  return CVESUCCESS;  
}  
 
int cvector_insert_at(const cvector cv, size_t index, void *memb)  
{  
  citerator iter;  
 
  if (index >= cv->cv_tot_len)   
  {  
    cv->cv_len = index + 1;  
    while (cv->cv_len >= cv->cv_tot_len) cv->cv_tot_len <<= EXPANED_VAL;  
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size);  
    iter = (char *)cv->cv_pdata + cv->cv_size * index;  
    memcpy(iter, memb, cv->cv_size);  
  }  
  else   
  {  
    iter = (char *)cv->cv_pdata + cv->cv_size * index;  
    cvector_insert(cv, iter, memb);  
  }  
 
  return 0;  
}  
 
citerator cvector_next(const cvector cv, citerator iter)  
{  
  return (char *)iter + cv->cv_size;  
}  
 
int cvector_val(const cvector cv, citerator iter, void *memb)  
{  
  memcpy(memb, iter, cv->cv_size);  
  return 0;  
}  
 
int cvector_val_at(const cvector cv, size_t index, void *memb)  
{  
  memcpy(memb, (char *)cv->cv_pdata + index * cv->cv_size, cv->cv_size);  
  return 0;  
}  
 
int cvector_rm(const cvector cv, citerator iter)  
{  
  citerator from;  
  citerator end;  
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__);  
  from = iter;  
  end = cvector_end(cv);  
  memcpy(from, (char *)from + cv->cv_size, (char *)end - (char *)from);  
  cv->cv_len--;  
 
  if ((cv->cv_tot_len >= (MIN_LEN << REDUSED_VAL))  
    && (cv->cv_len <= (cv->cv_tot_len >> REDUSED_VAL)))   
  {  
    void *pd_sav = cv->cv_pdata;  
    cv->cv_tot_len >>= EXPANED_VAL;  
    cv->cv_pdata = realloc(cv->cv_pdata, cv->cv_tot_len * cv->cv_size);  
 
    if (!cv->cv_pdata)   
    {  
      cv->cv_tot_len <<= EXPANED_VAL;  
      cv->cv_pdata = pd_sav;  
      return CVERM;  
    }  
  }  
 
  return CVESUCCESS;  
}  
 
int cvector_rm_at(const cvector cv, size_t index)  
{  
  citerator iter;  
  iter = (char *)cv->cv_pdata + cv->cv_size * index;  
  CWARNING_ITER(cv, iter, __FILE__, __func__, __LINE__);  
  return cvector_rm(cv, iter);  
}  
 
void cv_info(const cvector cv)  
{  
  printf("\n\ntot :%s : %d\n", __func__, cv->cv_tot_len);  
  printf("len :%s : %d\n",   __func__, cv->cv_len);  
  printf("size:%s : %d\n\n",  __func__, cv->cv_size);  
  return;  
}  
 
void cv_print(const cvector cv)  
{  
  int num;  
  citerator iter;  
 
  if (cvector_length(cv) == 0)  
    fprintf(stderr, "file:%s func:%s line:%d error, null length cvector!!\n", __FILE__, __func__, __LINE__);  
 
  for (iter = cvector_begin(cv);   
    iter != cvector_end(cv);  
    iter = cvector_next(cv, iter))   
  {  
    cvector_iter_val(cv, iter, &num);  
    printf("var:%d at:%d\n", num, cvector_iter_at(cv, iter));  
  }  
 
  return;  
}  

main.cpp

#include "cvector.h" 
 
int main() 
{ 
  int i = 1; 
  cvector cv = cvector_create(sizeof(int)); 
  cvector_pushback(cv, &i); 
  cvector_pushback(cv, &i); 
  cvector_pushback(cv, &i); 
  cvector_pushback(cv, &i); 
  cv_print(cv); 
  cvector_destroy(cv); 
  return 0; 
} 

更多精彩内容其他人还在看

用标准c++实现string与各种类型之间的转换

这个类在头文件中定义, < sstream>库定义了三种类:istringstream、ostringstream和stringstream,分别用来进行流的输入、输出和输入输出操作。另外,每个类都有一个对应的宽字符集版本
收藏 0 赞 0 分享

C++如何通过ostringstream实现任意类型转string

再使用整型转string的时候感觉有点棘手,因为itoa不是标准C里面的,而且即便是有itoa,其他类型转string不是很方便。后来去网上找了一下,发现有一个好方法
收藏 0 赞 0 分享

C/C++指针小结

要搞清一个指针需要搞清指针的四方面的内容:指针的类型,指针所指向的类型,指针的值或者叫指针所指向的内存区,还有指针本身所占据的内存区
收藏 0 赞 0 分享

C++ 类的静态成员深入解析

在C++中类的静态成员变量和静态成员函数是个容易出错的地方,本文先通过几个例子来总结静态成员变量和成员函数使用规则,再给出一个实例来加深印象
收藏 0 赞 0 分享

C++类的静态成员初始化详细讲解

通常静态数据成员在类声明中声明,在包含类方法的文件中初始化.初始化时使用作用域操作符来指出静态成员所属的类.但如果静态成员是整型或是枚举型const,则可以在类声明中初始化
收藏 0 赞 0 分享

C++类静态成员与类静态成员函数详解

静态成员不可在类体内进行赋值,因为它是被所有该类的对象所共享的。你在一个对象里给它赋值,其他对象里的该成员也会发生变化。为了避免混乱,所以不可在类体内进行赋值
收藏 0 赞 0 分享

C++中的friend友元函数详细解析

友元可以是一个函数,该函数被称为友元函数;友元也可以是一个类,该类被称为友元类。友元函数的特点是能够访问类中的私有成员的非成员函数。友元函数从语法上看,它与普通函数一样,即在定义上和调用上与普通函数一样
收藏 0 赞 0 分享

static全局变量与普通的全局变量的区别详细解析

以下是对static全局变量与普通的全局变量的区别进行了详细的分析介绍,需要的朋友可以过来参考下,希望对大家有所帮助
收藏 0 赞 0 分享

C++ explicit关键字的应用方法详细讲解

C++ explicit关键字用来修饰类的构造函数,表明该构造函数是显式的,既然有"显式"那么必然就有"隐式",那么什么是显示而什么又是隐式的呢?下面就让我们一起来看看这方面的知识吧
收藏 0 赞 0 分享

教你5分钟轻松搞定内存字节对齐

随便google一下,人家就可以跟你解释的,一大堆的道理,我们没怎么多时间,讨论为何要对齐.直入主题,怎么判断内存对齐规则,sizeof的结果怎么来的,请牢记以下3条原则
收藏 0 赞 0 分享
查看更多