我正在为我的应用程序编写一个输出管理器类，虽然我的类在 linux 下的 g++ 上运行，但它不会在 MSVC++ 2010 下编译。
这是我的程序的 SSCCE 版本:
#include <iostream>
#include <malloc.h>
#include <sstream>
#include <fstream>
template<class cT, class traits=std::char_traits<cT> >
class BasicE3OutStream: public std::basic_ostream<cT, traits> {
public:
BasicE3OutStream() :
std::basic_ios<cT, traits>(), std::basic_ostream<cT, traits>(0), mBuffer() {
resetModifiers();
mLineBuffer=(std::stringstream*) malloc(sizeof(std::stringstream));
mLineBuffer=new (mLineBuffer) std::stringstream();
}
BasicE3OutStream(const BasicE3OutStream<cT,traits> &) {
}
virtual ~BasicE3OutStream() {
delete mLineBuffer;
mLineBuffer=NULL;
}
void resetModifiers() {
mDebug=false;
mMemory=false;
}
void open(const char* fileName) {
mBuffer.open(fileName, std::stringstream::out);
}
void close() {
mBuffer.close();
}
template<class T>
BasicE3OutStream& operator<<(T val) {
(*mLineBuffer)<<val;
return (*this);
}
BasicE3OutStream& operator<<(char* val) {
(*mLineBuffer)<<val;
return (*this);
}
BasicE3OutStream& operator<<(std::string val) {
(*mLineBuffer)<<val;
return (*this);
}
void addLineFeed() {
std::string modifier;
modifier="";
if (mDebug)
modifier+="[DEBUG] ";
else if (mMemory)
modifier+="[MEMORY] ";
mBuffer<<modifier<<mLineBuffer->str()<<"\n";
mLineBuffer->~basic_stringstream();
mLineBuffer=new (mLineBuffer) std::stringstream();
resetModifiers();
}
void flush() {
mBuffer.flush();
resetModifiers();
}
void setFlag(int f) {
if (f==0)
mDebug=true;
else if (f==1)
mMemory=true;
}
public:
std::basic_ofstream<cT, traits> mBuffer;
std::stringstream* mLineBuffer;
bool mDebug, mMemory;
};
template<class cT, class traits, class T>
BasicE3OutStream<cT, traits>& operator<<(BasicE3OutStream<char, traits>& str , T val) {
str.operator <<(val);
return (str);
}
typedef BasicE3OutStream<char> E3OutStream;
template<class charT, class traits>
BasicE3OutStream<charT, traits>& endl(BasicE3OutStream<charT, traits>& os) {
os.addLineFeed();
return (os);
}
template<class charT, class traits>
BasicE3OutStream<charT, traits>& flush(BasicE3OutStream<charT, traits>& os) {
os.flush();
return (os);
}
template<class charT, class traits>
BasicE3OutStream<charT, traits>& debug(BasicE3OutStream<charT, traits>& os) {
os.setFlag(0);
return (os);
}
template<class charT, class traits>
BasicE3OutStream<charT, traits>& memory(BasicE3OutStream<charT, traits>& os) {
os.setFlag(1);
return (os);
}
/**
* Io manipulator, allows to use endl and other modificators
*/
template<class charT, class traits> BasicE3OutStream<charT, traits>& operator<<(
BasicE3OutStream<charT, traits> &s
, BasicE3OutStream<charT, traits>& (*iomanip)(BasicE3OutStream<charT, traits>&)) {
return (iomanip(s));
}
int main() {
E3OutStream s;
s.open("output.txt");
s<<debug<<"Debug info"<<endl;
s<<flush;
s<<memory<<"Memory info"<<endl;
s<<flush;
s.close();
}
它在 g++ 中运行良好，但是在 MSVC 上我得到一个编译器错误:
1>------ Build started: Project: sscce, Configuration: Debug Win32 ------
1> main.cpp
1>c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(129): error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'overloaded-function' (or there is no acceptable conversion)
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(679): could be 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)' [found using argument-dependent lookup]
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\ostream(726): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)' [found using argument-dependent lookup]
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\ostream(764): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)' [found using argument-dependent lookup]
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\ostream(811): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)' [found using argument-dependent lookup]
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\ostream(937): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const signed char *)' [found using argument-dependent lookup]
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\ostream(944): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,signed char)' [found using argument-dependent lookup]
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\ostream(951): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const unsigned char *)' [found using argument-dependent lookup]
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\ostream(958): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,unsigned char)' [found using argument-dependent lookup]
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\ostream(1085): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const std::error_code &)' [found using argument-dependent lookup]
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(43): or 'BasicE3OutStream<cT> &BasicE3OutStream<cT>::operator <<(char *)'
1> with
1> [
1> cT=char
1> ]
1> c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(48): or 'BasicE3OutStream<cT> &BasicE3OutStream<cT>::operator <<(std::string)'
1> with
1> [
1> cT=char
1> ]
1> while trying to match the argument list '(E3OutStream, overloaded-function)'
1>c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(130): error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'overloaded-function' (or there is no acceptable conversion)
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(679): could be 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)' [found using argument-dependent lookup]
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\ostream(726): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)' [found using argument-dependent lookup]
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\ostream(764): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)' [found using argument-dependent lookup]
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\ostream(811): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)' [found using argument-dependent lookup]
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\ostream(937): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const signed char *)' [found using argument-dependent lookup]
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\ostream(944): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,signed char)' [found using argument-dependent lookup]
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\ostream(951): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const unsigned char *)' [found using argument-dependent lookup]
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\ostream(958): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,unsigned char)' [found using argument-dependent lookup]
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\ostream(1085): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const std::error_code &)' [found using argument-dependent lookup]
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(43): or 'BasicE3OutStream<cT> &BasicE3OutStream<cT>::operator <<(char *)'
1> with
1> [
1> cT=char
1> ]
1> c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(48): or 'BasicE3OutStream<cT> &BasicE3OutStream<cT>::operator <<(std::string)'
1> with
1> [
1> cT=char
1> ]
1> while trying to match the argument list '(E3OutStream, overloaded-function)'
1>c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(131): error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'overloaded-function' (or there is no acceptable conversion)
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(679): could be 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)' [found using argument-dependent lookup]
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\ostream(726): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)' [found using argument-dependent lookup]
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\ostream(764): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)' [found using argument-dependent lookup]
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\ostream(811): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)' [found using argument-dependent lookup]
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\ostream(937): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const signed char *)' [found using argument-dependent lookup]
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\ostream(944): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,signed char)' [found using argument-dependent lookup]
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\ostream(951): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const unsigned char *)' [found using argument-dependent lookup]
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\ostream(958): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,unsigned char)' [found using argument-dependent lookup]
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\ostream(1085): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const std::error_code &)' [found using argument-dependent lookup]
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(43): or 'BasicE3OutStream<cT> &BasicE3OutStream<cT>::operator <<(char *)'
1> with
1> [
1> cT=char
1> ]
1> c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(48): or 'BasicE3OutStream<cT> &BasicE3OutStream<cT>::operator <<(std::string)'
1> with
1> [
1> cT=char
1> ]
1> while trying to match the argument list '(E3OutStream, overloaded-function)'
1>c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(132): error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'overloaded-function' (or there is no acceptable conversion)
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ostream(679): could be 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)' [found using argument-dependent lookup]
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\ostream(726): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)' [found using argument-dependent lookup]
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\ostream(764): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)' [found using argument-dependent lookup]
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\ostream(811): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)' [found using argument-dependent lookup]
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\ostream(937): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const signed char *)' [found using argument-dependent lookup]
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\ostream(944): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,signed char)' [found using argument-dependent lookup]
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\ostream(951): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const unsigned char *)' [found using argument-dependent lookup]
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\ostream(958): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,unsigned char)' [found using argument-dependent lookup]
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\ostream(1085): or 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const std::error_code &)' [found using argument-dependent lookup]
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(43): or 'BasicE3OutStream<cT> &BasicE3OutStream<cT>::operator <<(char *)'
1> with
1> [
1> cT=char
1> ]
1> c:\users\guillaume\documents\visual studio 2010\projects\sscce\sscce\main.cpp(48): or 'BasicE3OutStream<cT> &BasicE3OutStream<cT>::operator <<(std::string)'
1> with
1> [
1> cT=char
1> ]
1> while trying to match the argument list '(E3OutStream, overloaded-function)'
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
任何帮助将不胜感激， 纪尧姆
[编辑]
多亏了这个建议，我才意识到扩展 iostream 在那种情况下没有用，因为我已经有一个 ofstream 作为成员变量。由于我对 std 库的内部工作了解不够，我让我的类独立并且它在 MSVC 和 g++ 上工作:
#include <iostream>
#include <malloc.h>
#include <sstream>
#include <fstream>
class BasicE3OutStream {
public:
BasicE3OutStream() :
mBuffer() {
resetModifiers();
mLineBuffer=(std::stringstream*) malloc(sizeof(std::stringstream));
mLineBuffer=new (mLineBuffer) std::stringstream();
}
BasicE3OutStream(const BasicE3OutStream &) {
}
virtual ~BasicE3OutStream() {
delete mLineBuffer;
mLineBuffer=NULL;
}
void resetModifiers() {
mDebug=false;
mMemory=false;
}
void open(const char* fileName) {
mBuffer.open(fileName, std::stringstream::out);
}
void close() {
mBuffer.close();
}
template<class T>
BasicE3OutStream& operator<<(T val) {
(*mLineBuffer)<<val;
return (*this);
}
void addLineFeed() {
std::string modifier;
modifier="";
if (mDebug)
modifier+="[DEBUG] ";
else if (mMemory)
modifier+="[MEMORY] ";
mBuffer<<modifier<<mLineBuffer->str()<<"\n";
mLineBuffer->str("");
resetModifiers();
}
void flush() {
mBuffer.flush();
resetModifiers();
}
void setFlag(int f) {
if (f==0)
mDebug=true;
else if (f==1)
mMemory=true;
}
public:
std::ofstream mBuffer;
std::stringstream* mLineBuffer;
bool mDebug, mMemory;
};
BasicE3OutStream& endl(BasicE3OutStream& os) {
os.addLineFeed();
return (os);
}
BasicE3OutStream& flush(BasicE3OutStream& os) {
os.flush();
return (os);
}
BasicE3OutStream& debug(BasicE3OutStream& os) {
os.setFlag(0);
return (os);
}
BasicE3OutStream& memory(BasicE3OutStream& os) {
os.setFlag(1);
return (os);
}
/**
* Io manipulator, allows to use endl and other modificators
*/
BasicE3OutStream& operator<<(
BasicE3OutStream &s
, BasicE3OutStream& (*iomanip)(BasicE3OutStream&)) {
return (iomanip(s));
}
typedef BasicE3OutStream E3OutStream;
int main() {
E3OutStream s;
s.open("output.txt");
s<<debug<<"Debug info"<<endl;
s<<flush;
s<<memory<<"Memory info"<<endl;
s<<flush;
s.close();
}
最佳答案
问题的核心是您将函数指针发送到您的流，GCC 似乎知道如何处理，但 MSVC++ 不知道。不管怎样，我怀疑你想保存 debug 的地址/endl/flush/memory功能。
下一步的解决方案是制作那些对象，而不是您显示的函数。
但是，这段代码有一个很多错误。即，已经存在endl和 flush你应该使用的对象。此外，每个 BasicE3OutStream有 三个 底层流，它继承自一个，所有函数都在其上工作，(包括 endl 等等，我想这就是你替换它们的原因)，和 mBuffer和 mLineBuffer ，(您正在做的事情都不需要任何成员)。 (另一方面，用 mLineBuffer.str(""); 重置字符串流，而不是新的位置)
做你想做的事情的简单方法是重载每个 operator<<成员basic_ostream , 在有换行符的地方插入 [DEBUG]或 [MEMORY]视情况而定，无需缓冲。 (我已经做到了，这并不难)
可能有一种正确的方法可以通过使用具有不同字符特征的流，或者重载某些虚函数，或者替换缓冲区来实现这一点，但是流很复杂，我不知道这个正确方式。
关于c++ - MSVC++ 扩展 iostream 时出错，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/9398391/