自定义流对象错误?
Custom stream object error?
我正在尝试编写一个程序:
parses text, removes pre-specified (punctuation) characters and creates a alphabetically ordered dictionary containing the parsed words from the text, which are then displayed on the screen. From Bjarne Stroustup's C++ Programming: Principle and Practice
这是我写的:
Chapter11Exercise7Execute.cpp
#include "stdAfx.h"
#include "Chapter11Exercise7.h"
const string endInput("x");
int main(){
try{
// instantiate a PunctStream object and initialize it to: cin
PunctStream ps(cin);
// construct initial set of characters to be replaced with whitepace
ps.whitespace(",");
// set case sensitivity
ps.caseSensitive(false);
string word;
vector<string> dictionary;
do{
cout << "Type a word\n>>";
cin >> word;
createDictionary(ps, dictionary);
printDictionary(dictionary);
}while(word != endInput);
}catch(exception& e){
cerr << e.what() << endl;
getchar();
}
return 0;
}
Chapter11Exercise7.h
#include "stdAfx.h"
#ifndef _Chapter11Exercise7_H
#define _Chapter11Exercise7_H
class PunctStream{
public:
// constructors
PunctStream(istream& is): source(is), sensitive(true){ }
// member-functions
// creates a set of characters to be searched and replaced with whitespace
void whitespace(const string& s){white = s;};
void addWhitespace(char c){white += c;};
bool isWhitespace(char c);
// set case sensitivity
void caseSensitive(bool b){sensitive = b;};
bool isCaseSensitive(){return sensitive;};
// overwritten extraction operator
PunctStream& operator>>(string& s);
// operator that returns a bool value on success/failure of PunctStream object
operator bool();
private:
// stream containing text to be parsed
istream source;
// stringstream containing a parsed text
istringstream buffer;
// case sensitivity
bool sensitive;
// characters to be replaced with whitespace
string white;
};
// Non-member functions
void createDictionary(PunctStream& ps, vector<string>& d);
void printDictionary(vector<string>& d);
#include "Chapter11Exercise7V1.cpp"
#endif
Chapter11Exercise7.cpp
#include "Chapter11Exercise7.h"
// Member functions definition
bool PunctStream::isWhitespace(char c){
for(size_t i; i < white.size(); i++) if (c == white[i]) return true;
return false;
}
// Overwritten operators definition
PunctStream& PunctStream::operator>>(string& s){
while(!(buffer >> s)){
// if buffer bad() or source not food => return PunctStream object
// this is a pointe to the object in context
if(buffer.bad() || !source.good()) return *this;
buffer.clear();
string line;
// get a line from source
getline(source, line);
// replace "white" characters in "line"
for(size_t i = 0; i < line.size(); ++i){
if(isWhitespace(line[i])) line[i] = ' ';
// if case sensitivity is set => convert to lowercase
else if (!sensitive) line[i] = tolower(line[i]);
}
// initialize the stringstream buffer to "line"
buffer.str(line);
}
return *this;
}
PunctStream::operator bool(){
// to return true: fail() and bas() should be unset, good()-set
return !(source.fail() || source.bad()) && source.good();
}
// Non-member functions
void createDictionary(PunctStream& ps, vector<string>& d){
string word;
while(ps >> word) d.push_back(word);
sort(d.begin(), d.end());
}
void printDictionary(vector<string>& d){
for(size_t i = 0; i < d.size(); ++i) cout << d[i] <<'\n';
}
我得到的错误如下:
1>------ Build started: Project: bjarneStroustroupC, Configuration: Debug Win32 ------
1> Chapter11Exercise7Execute.cpp
1>c:\program files (x86)\microsoft visual studio 10.0\vc\include\istream(860): error C2248: 'std::basic_ios<_Elem,_Traits>::basic_ios' : cannot access private member declared in class 'std::basic_ios<_Elem,_Traits>'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ios(176) : see declaration of 'std::basic_ios<_Elem,_Traits>::basic_ios'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> This diagnostic occurred in the compiler generated function 'std::basic_istream<_Elem,_Traits>::basic_istream(const std::basic_istream<_Elem,_Traits> &)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
我已阅读错误消息,但它没有响铃。欢迎任何见解或建议!
这是您尝试复制 istream
对象时收到的错误消息,因为 istream
不可复制。我认为这特别发生在这里:
class PunctStream{
public:
PunctStream(istream& is): source(is), sensitive(true){ }
private:
istream source;
};
在这里,您试图将 source
数据成员初始化为输入流参数 is
的副本,因此出现错误。
要解决此问题,请考虑将 source
更改为 istream&
- 对 istream
的引用 - 而不是具体的 istream
对象。
希望对您有所帮助!
我正在尝试编写一个程序:
parses text, removes pre-specified (punctuation) characters and creates a alphabetically ordered dictionary containing the parsed words from the text, which are then displayed on the screen. From Bjarne Stroustup's C++ Programming: Principle and Practice
这是我写的:
Chapter11Exercise7Execute.cpp
#include "stdAfx.h"
#include "Chapter11Exercise7.h"
const string endInput("x");
int main(){
try{
// instantiate a PunctStream object and initialize it to: cin
PunctStream ps(cin);
// construct initial set of characters to be replaced with whitepace
ps.whitespace(",");
// set case sensitivity
ps.caseSensitive(false);
string word;
vector<string> dictionary;
do{
cout << "Type a word\n>>";
cin >> word;
createDictionary(ps, dictionary);
printDictionary(dictionary);
}while(word != endInput);
}catch(exception& e){
cerr << e.what() << endl;
getchar();
}
return 0;
}
Chapter11Exercise7.h
#include "stdAfx.h"
#ifndef _Chapter11Exercise7_H
#define _Chapter11Exercise7_H
class PunctStream{
public:
// constructors
PunctStream(istream& is): source(is), sensitive(true){ }
// member-functions
// creates a set of characters to be searched and replaced with whitespace
void whitespace(const string& s){white = s;};
void addWhitespace(char c){white += c;};
bool isWhitespace(char c);
// set case sensitivity
void caseSensitive(bool b){sensitive = b;};
bool isCaseSensitive(){return sensitive;};
// overwritten extraction operator
PunctStream& operator>>(string& s);
// operator that returns a bool value on success/failure of PunctStream object
operator bool();
private:
// stream containing text to be parsed
istream source;
// stringstream containing a parsed text
istringstream buffer;
// case sensitivity
bool sensitive;
// characters to be replaced with whitespace
string white;
};
// Non-member functions
void createDictionary(PunctStream& ps, vector<string>& d);
void printDictionary(vector<string>& d);
#include "Chapter11Exercise7V1.cpp"
#endif
Chapter11Exercise7.cpp
#include "Chapter11Exercise7.h"
// Member functions definition
bool PunctStream::isWhitespace(char c){
for(size_t i; i < white.size(); i++) if (c == white[i]) return true;
return false;
}
// Overwritten operators definition
PunctStream& PunctStream::operator>>(string& s){
while(!(buffer >> s)){
// if buffer bad() or source not food => return PunctStream object
// this is a pointe to the object in context
if(buffer.bad() || !source.good()) return *this;
buffer.clear();
string line;
// get a line from source
getline(source, line);
// replace "white" characters in "line"
for(size_t i = 0; i < line.size(); ++i){
if(isWhitespace(line[i])) line[i] = ' ';
// if case sensitivity is set => convert to lowercase
else if (!sensitive) line[i] = tolower(line[i]);
}
// initialize the stringstream buffer to "line"
buffer.str(line);
}
return *this;
}
PunctStream::operator bool(){
// to return true: fail() and bas() should be unset, good()-set
return !(source.fail() || source.bad()) && source.good();
}
// Non-member functions
void createDictionary(PunctStream& ps, vector<string>& d){
string word;
while(ps >> word) d.push_back(word);
sort(d.begin(), d.end());
}
void printDictionary(vector<string>& d){
for(size_t i = 0; i < d.size(); ++i) cout << d[i] <<'\n';
}
我得到的错误如下:
1>------ Build started: Project: bjarneStroustroupC, Configuration: Debug Win32 ------
1> Chapter11Exercise7Execute.cpp
1>c:\program files (x86)\microsoft visual studio 10.0\vc\include\istream(860): error C2248: 'std::basic_ios<_Elem,_Traits>::basic_ios' : cannot access private member declared in class 'std::basic_ios<_Elem,_Traits>'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ios(176) : see declaration of 'std::basic_ios<_Elem,_Traits>::basic_ios'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> This diagnostic occurred in the compiler generated function 'std::basic_istream<_Elem,_Traits>::basic_istream(const std::basic_istream<_Elem,_Traits> &)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
我已阅读错误消息,但它没有响铃。欢迎任何见解或建议!
这是您尝试复制 istream
对象时收到的错误消息,因为 istream
不可复制。我认为这特别发生在这里:
class PunctStream{
public:
PunctStream(istream& is): source(is), sensitive(true){ }
private:
istream source;
};
在这里,您试图将 source
数据成员初始化为输入流参数 is
的副本,因此出现错误。
要解决此问题,请考虑将 source
更改为 istream&
- 对 istream
的引用 - 而不是具体的 istream
对象。
希望对您有所帮助!