本文介绍了当使用inside while循环时，跨越'std :: istringstream iss'的初始化的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
当我在 std :: istringstream iss（std :: move（result_string））; 里面，然后它给出错误。
实际上，我得到我的字符串 result_string 里面，所以我必须执行 move 。 >
我可以这样初始化iss：
std :: istringstream iss
现在如何执行移动操作将字符串（result_string）中的缓冲区重新分配到流？意味着我可以如何执行（std :: move（s））里面？
我的原始代码： / p>
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，
这是整个代码，如果你想看到：
#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>
#includedictionary.h
#pragma忽略GCC诊断-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（初始化套接字％dn时出错，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， p_int，sizeof（int））== -1））{
printf（错误设置选项％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 bind to socket， else is listening on this port％dn，errno）;
goto FINISH;
}
if（listen（hsock，10）== -1）{
fprintf（stderr，Error listening％dn，errno）;
goto FINISH;
}
//现在让服务器的东西
addr_size = sizeof（sockaddr_in）;
while（true）{
printf（waiting for a connectionn \\\
）;
csock =（int *）malloc（sizeof（int））;
if（（* csock = accept（hsock，（sockaddr *）& sadr，& addr_size））！= -1）{
printf（---------- ----------- n接收到来自％s\\\
的连接，inet_ntoa（sadr.sin_addr））;
pthread_create（& thread_id，0，& SocketHandler，（void *）csock）;
pthread_detach（thread_id）;
} else {
fprintf（stderr，Error accepting％dn，errno）;
}
}
完成：
;
}
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>最;
int max_count = 0;
typedef std :: unordered_map< std :: string，int>发生;
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} / *存储引用50个字。 * /
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 \\\
，errno）;
goto FINISH;
}
printf（Received bytes％d \\\
Received string％s \\\
，bytecount，buffer）;
word = strtok（buffer，）;
while（（NULL！= word）&&（50> i））{
ch [i] = strdup
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 \\\
，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<< \\\
;
std :: istringstream iss（std :: move（result_string））;
//提取字符串直到endl，获取每个单词和单词的计数值，最大计数值
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< 最大出现次数< 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）{//这里我们不能发送lenth-1。它认为确切
fprintf（stderr，发送数据错误％d \\\
，errno）;
goto FINISH;
}
完成：
free（csock）;
return 0;
}
解决方案
在StackOverflow.com上无效。你必须在论坛中提出这个问题。
问题在这里：
std： ：string s =一二二三一一二;
std :: istringstream iss（std :: move（s））;
while（iss>> s）
{
int tmp = ++ s1 [s];
您正在尝试在while循环中初始化变量（int tmp）。如果你是一台计算机，这就是你看到的：做一个条件循环（正确），用这个计算初始化一个名为tmp的新变量。
一旦循环到第二个itteration，你告诉他，'初始化一个新变量tmp与这个计算'，但tmp已经初始化，因此它是一个错误。
解决方案是：
std :: string s =一二二三一一二;
std :: istringstream iss（std :: move（s））;
int tmp;
while（iss>> s）
{
tmp = ++ s1 [s];
When I take std::istringstream iss(std::move(result_string)); inside while then it gives error. Actually I get my string result_string inside while, so I have to perform move there.
I can initialize iss like this:std::istringstream iss
Now How can I perform move operation to reassign buffer from string(result_string) to stream? means how can I perform (std::move(s)) inside while?
my original code:
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);
}
}
But when entire code is in while loop, it gives error.
this is entire code if you want to see:
#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;
}
解决方案
The question is valid, but not valid on StackOverflow.com. You must ask this question in a forum. See the rules.
The problem lies here:
std::string s = "one two two three one one two";
std::istringstream iss(std::move(s));
while (iss >> s)
{
int tmp = ++s1[s];
You are trying to initialize a variable (int tmp) in a while loop. If you are a computer then this is what you see: Do a while loop with a condition (correct), initialize a NEW variable called tmp with this calculation. Once the loop goes to the second itteration, you tell him, 'initialize a NEW variable called tmp with this calculation', but tmp was already initialized and therefore it's a error.
The solution is:
std::string s = "one two two three one one two";
std::istringstream iss(std::move(s));
int tmp;
while (iss >> s)
{
tmp = ++s1[s];
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