当我将std::istringstream iss(std::move(result_string));置于内部时，它会出错。
实际上我在里面得到了我的字符串result_string，所以我必须在那里执行move。
我可以像这样初始化iss：
std::istringstream iss
现在如何执行移动操作以将缓冲区从字符串（result_string）重新分配给流？意味着如何在内部执行(std::move(s))？
我的原始代码：
std::string s = "one two two three one one two";
std::istringstream iss(std::move(s));
while (iss >> s)
{
int tmp = ++s1[s];
if (tmp == max_count)
{
most.push_back(s);
}
else if (tmp > max_count)
{
max_count = tmp;
most.clear();
most.push_back(s);
}
}
但是当整个代码在while循环中时，它会给出错误。
如果你想看到这是完整的代码：
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <netinet/in.h>
#include <resolv.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <iostream>
#include <stdio.h>
#include <netinet/in.h>
#include <resolv.h>
#include <sys/socket.h>
#include <unistd.h>
#include <vector>
#include <sstream>
#include <algorithm>
#include <unordered_map>
#include <pthread.h>
#include <iostream>
#include <sstream>
#include <cstdio>
#include "dictionary.h"
#pragma GCC diagnostic ignored "-Wwrite-strings"
using namespace std;
void *SocketHandler(void *);
int main(int argv, char **argc)
{
int host_port = 1103;
char buf[20];
int k;
struct sockaddr_in my_addr;
int hsock;
int *p_int;
int err;
socklen_t addr_size = 0;
int *csock;
sockaddr_in sadr;
pthread_t thread_id = 0;
hsock = socket(AF_INET, SOCK_STREAM, 0);
if (hsock == -1) {
printf("Error initializing socket %dn", errno);
goto FINISH;
}
p_int = (int *) malloc(sizeof(int));
*p_int = 1;
if ((setsockopt(hsock, SOL_SOCKET, SO_REUSEADDR, (char *) p_int, sizeof(int)) == -1) || (setsockopt(hsock, SOL_SOCKET, SO_KEEPALIVE, (char *) p_int, sizeof(int)) == -1)) {
printf("Error setting options %dn", errno);
free(p_int);
goto FINISH;
}
free(p_int);
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(host_port);
memset(&(my_addr.sin_zero), 0, 8);
my_addr.sin_addr.s_addr = INADDR_ANY;
if (bind(hsock, (sockaddr *) & my_addr, sizeof(my_addr)) == -1) {
fprintf(stderr, "Error binding to socket, make sure nothing else is listening on this port %dn", errno);
goto FINISH;
}
if (listen(hsock, 10) == -1) {
fprintf(stderr, "Error listening %dn", errno);
goto FINISH;
}
//Now lets do the server stuff
addr_size = sizeof(sockaddr_in);
while (true) {
printf("waiting for a connectionn\n");
csock = (int *) malloc(sizeof(int));
if ((*csock = accept(hsock, (sockaddr *) & sadr, &addr_size)) != -1) {
printf("---------------------nReceived connection from %s\n", inet_ntoa(sadr.sin_addr));
pthread_create(&thread_id, 0, &SocketHandler, (void *) csock);
pthread_detach(thread_id);
} else {
fprintf(stderr, "Error accepting %dn", errno);
}
}
FINISH:
;
}
void *SocketHandler(void *lp)
{
int ar[2];
int result=0;
int *csock = (int *) lp;
char buf[20];
int k;
char *skp;
char *str;
char *str2;
std::string ss;
std::ostringstream bfr;
std::string result_string;
std::vector<std::string> most;
int max_count = 0;
typedef std::unordered_map<std::string,int> occurrences;
occurrences s1;
int pcount = 0, ncount = 0;
char buffer[1024];
int buffer_len = 1024;
int bytecount;
int i = 0,t=0,q=0;
int j = 0;
char *ch[50] = { 0 }; /* stores references to 50 words. */
char *ch2[50] = { 0 };
char *excluded_string[50] = { 0 };
char *word = strtok(buffer, " ");
char *word2 = strtok(buffer, " ");
char *portstring1=(char *)malloc(sizeof(buffer));
char *portstring2=(char *)malloc(sizeof(buffer));
memset(buffer, 0, buffer_len);
if ((bytecount = recv(*csock, buffer, buffer_len, 0)) == -1) {
fprintf(stderr, "Error receiving data %d \n", errno);
goto FINISH;
}
printf("Received bytes %d \nReceived string %s \n ", bytecount, buffer);
word = strtok(buffer, " ");
while ((NULL != word) && (50 > i)) {
ch[i] = strdup(word);
excluded_string[j]=strdup(word);
word = strtok(NULL, " ");
skp = BoyerMoore_skip(ch[i], strlen(ch[i]) );
if(skp != NULL)
{
i++;
continue;
}
printf("exclueded : %s and %s size %d \n",excluded_string[j],ch[i],sizeof(excluded_string));
bfr << excluded_string[j] << " ";
result_string = bfr.str();
j++;
// std::cout << "string is :" << r1;
str = BoyerMoore_positive(ch[i], strlen(ch[i]) );
str2= BoyerMoore_negative(ch[i], strlen(ch[i]) );
if (str == NULL)
t++;
else {
pcount += 1;
}
if(str2== NULL)
q++;
else
ncount += 1;
i++;
if(str==NULL && str==NULL and skp !=NULL)
{
pcount=0;
ncount=0;
}
}
std::cout << "string is :" << result_string << "\n";
std::istringstream iss(std::move(result_string));
//extract the string till endl, get count values for each word and word with max count value
while (iss >> result_string)
{
int tmp = ++s1[result_string];
if (tmp == max_count)
{
most.push_back(result_string);
}
else if (tmp > max_count)
{
max_count = tmp;
most.clear();
most.push_back(result_string);
}
}
std::cout << std::endl << "Maximum Occurrences" << std::endl;
for (std::vector<std::string>::const_iterator it = most.cbegin(); it != most.cend(); ++it)
std::cout << *it << std::endl;
ar[0]=pcount;
ar[1]=ncount;
if ((bytecount = send(*csock, (char *)ar, 2 *sizeof(int), 0)) == -1) { // Here we cant send lenth-1. It consider exact
fprintf(stderr, "Error sending data %d\n", errno);
goto FINISH;
}
FINISH:
free(csock);
return 0;
}
答案 0 :(得分：1)
该问题有效，但在StackOverflow.com上无效。你必须在论坛中提出这个问题。请参阅规则。
问题在于：
std::string s = "one two two three one one two";
std::istringstream iss(std::move(s));
while (iss >> s)
{
int tmp = ++s1[s];
您正尝试在while循环中初始化变量（int tmp）。如果您是计算机，那么这就是您所看到的：使用条件执行while循环（正确），使用此计算初始化名为tmp的NEW变量。 一旦循环进入第二次迭代，你告诉他'用这个计算初始化一个叫做tmp的新变量'，但是tmp已经初始化了，因此它是一个错误。
解决方案是：
std::string s = "one two two three one one two";
std::istringstream iss(std::move(s));
int tmp;
while (iss >> s)
{
tmp = ++s1[s];