与g ++ 4.8.3相比，下面的代码需要永远（好吧，长时间）在g ++ 6.1.0中进行编译。这是编译器错误吗？或者代码中有些愚蠢的东西？ （愚蠢而不是使用没有浮点值的固定和showpoint ...）。
g ++ 4.8：
$时间 〜/ dev / compilers / linux-x86_64-2.10.1 / gnu4.8.3 / bin / g ++ -D_REENTRANT -fPIC -Wall -Wextra -Wno-unused-parameter -Werror -Wno-unused-local-typedefs -m64 -Woverloaded-virtual -Wno-deprecated -fvisibility-inlines-hidden -fvisibility = hidden -std = c ++ 11 -c ostreamtest.cpp
真正的0m0.451s
g ++ 6.1：
$时间 〜/ dev / compilers / linux-x86_64-2.10.1 / gnu6.1.0 / bin / g ++ -D_REENTRANT -fPIC -Wall -Wextra -Wno-unused-parameter -Werror -Wno-unused-local-typedefs -m64 -Woverloaded-virtual -Wno-deprecated -fvisibility-inlines-hidden -fvisibility = hidden -std = c ++ 11 -c ostreamtest.cpp
真正的15m36.033s
ostreamtest.cpp：
#include <iostream>
#include <iomanip>
#include <ostream>
typedef long long int64;
class IOStreamWrapper
{
public:
/// get/set ALL format flags
virtual std::ios_base::fmtflags flags() const;
virtual std::ios_base::fmtflags flags(std::ios_base::fmtflags flags);
/// set specific format flags
virtual std::ios_base::fmtflags setf(std::ios_base::fmtflags flags);
virtual std::ios_base::fmtflags setf(std::ios_base::fmtflags flags, std::ios_base::fmtflags mask);
/// unset specific format flags
virtual void unsetf(std::ios_base::fmtflags mask);
/// get/set precision
virtual std::streamsize precision() const;
virtual std::streamsize precision(std::streamsize precision);
/// get/set width
virtual std::streamsize width() const;
virtual std::streamsize width(std::streamsize wide);
/// get/set fill char
virtual char fill() const;
virtual char fill(char c);
/// stream error states
virtual bool good();
virtual bool bad();
virtual bool fail();
virtual bool eof();
virtual void clear();
// Forward conversion to bool to the real istream.
virtual operator int();
// forward operators void* (returns !fail())
virtual operator void*();
// forward operator !() (returns fail() )
virtual bool operator !();
/// dummy method which allows use of broadcast and nobroadcast manipulators
/// in the InputFileStream and OutputFileStream classes. Not perfect but the
/// only way I could this to work.
virtual void setBroadcastFlag(bool const &flag = true) { return; }
protected:
// Construct class to reference a real istream. All methods and
// operators will be forwarded.
IOStreamWrapper(std::ios &ios);
IOStreamWrapper(IOStreamWrapper const &r);
virtual ~IOStreamWrapper() {}
// Reference to the real ostream.
std::ios & iostr() { return _iostr; }
std::ios const & iostr() const { return _iostr; }
private:
// Reference to the real iostream.
std::ios &_iostr;
IOStreamWrapper &operator=(IOStreamWrapper const &r); // Not Implemented.
};
class Indent;
class OStreamWrapper: public IOStreamWrapper
{
public:
// Construct class to reference a real ostream. All methods and
// operators will be forwarded.
OStreamWrapper(std::ostream &os);
OStreamWrapper(OStreamWrapper const &r);
virtual ~OStreamWrapper() {}
// Type for a fake endl.
struct EndlType {};
// Forward this output operator to the real ostream.
OStreamWrapper & operator << (EndlType const &);
OStreamWrapper & operator << (Indent const &);
// wrappers for ostream global functions
virtual OStreamWrapper & operator<<(char c);
virtual OStreamWrapper & operator<<(unsigned char c);
virtual OStreamWrapper & operator<<(char const * s);
virtual OStreamWrapper & operator<<(unsigned char const * s);
virtual OStreamWrapper & operator<<(std::string);
// wrappers for ostream member functions
virtual OStreamWrapper & operator << (bool);
virtual OStreamWrapper & operator << (short);
virtual OStreamWrapper & operator << (unsigned short);
virtual OStreamWrapper & operator << (int);
virtual OStreamWrapper & operator << (unsigned int);
virtual OStreamWrapper & operator << (long);
virtual OStreamWrapper & operator << (unsigned long);
virtual OStreamWrapper & operator << (long long);
virtual OStreamWrapper & operator << (unsigned long long);
virtual OStreamWrapper & operator << (float);
virtual OStreamWrapper & operator << (double);
virtual OStreamWrapper & operator << (long double);
virtual OStreamWrapper & operator << (void*);
virtual OStreamWrapper & operator << (std::streambuf* sb);
virtual OStreamWrapper & operator << (OStreamWrapper &(*manpip)(OStreamWrapper &));
virtual OStreamWrapper & operator << (std::ostream &(*manpip)(std::ostream &));
virtual OStreamWrapper & operator << (std::ios &(*manip)(std::ios &));
virtual OStreamWrapper & operator << (std::ios_base &(*manip)(std::ios_base &));
OStreamWrapper & operator << (void (*)(void*));
OStreamWrapper & operator << (void* (*)(void*));
OStreamWrapper & operator << (int (*)(void*));
OStreamWrapper & operator << (int* (*)(void*));
OStreamWrapper & operator << (float* (*)(void*));
OStreamWrapper & operator << (char const* (*)(void*));
OStreamWrapper & operator << (void (*)(void*, int*));
// Forward ostream methods directly to the ostream
virtual OStreamWrapper & write(char const*, std::streamsize);
virtual OStreamWrapper & flush();
virtual OStreamWrapper & put(char c);
virtual OStreamWrapper & seekp(std::streampos pos);
virtual OStreamWrapper & seekp(std::streamoff offset, std::ios_base::seekdir dir);
virtual std::streampos tellp();
/// switch for broadcast flag in InputFileStream class
static OStreamWrapper & broadcast(OStreamWrapper &);
static OStreamWrapper & nobroadcast(OStreamWrapper &);
// Get a reference to the real ostream.
std::ostream & GetOStream();
// Allow conversion to the real ostream type. This allows an
// instance of OStreamWrapper to look like ostream when passing to a
// function argument.
operator std::ostream&();
// Implementation detail to allow macros to provide an endl that may
// or may not be used.
static void UseEndl(EndlType const &) {}
// wrap std manipulators
class setw{
public:
explicit setw(int const &i) : _i(i) {}
private:
friend OStreamWrapper & operator<<(OStreamWrapper &ib, setw const &m)
{
ib.width(m._i);
return ib;
}
int _i;
};
class setprecision{
public:
explicit setprecision(int const &i) : _i(i) {}
private:
friend OStreamWrapper & operator<<(OStreamWrapper &ib, setprecision const &m)
{
ib.precision(m._i);
return ib;
}
int _i;
};
class setfill{
public:
explicit setfill(char c) : _c(c) {}
private:
friend OStreamWrapper & operator<<(OStreamWrapper &ib, setfill const &m)
{
ib.fill(m._c);
return ib;
}
char _c;
};
class setiosflag{
public:
explicit setiosflag(std::ios_base::fmtflags mask) : _mask(mask) {}
private:
friend OStreamWrapper & operator<<(OStreamWrapper &ib, setiosflag const &m)
{
ib.setf(m._mask);
return ib;
}
std::ios_base::fmtflags _mask;
};
class resetiosflag{
public:
explicit resetiosflag(std::ios_base::fmtflags mask) : _mask(mask) {}
private:
friend OStreamWrapper & operator<<(OStreamWrapper &ib, resetiosflag const &m)
{
ib.unsetf(m._mask);
return ib;
}
std::ios_base::fmtflags _mask;
};
protected:
// Reference to the real ostream.
std::ostream & ostr() { return _ostr; }
std::ostream const & ostr() const { return _ostr; }
private:
// Reference to the real ostream.
std::ostream &_ostr;
OStreamWrapper & operator=(OStreamWrapper const &r); // Not Implemented.
};
void
printProcessTableData(OStreamWrapper &out,
int const maxLen,
int const columnWidth,
int const nColumns,
std::string const &tag,
double const resMem,
double const addedResMem,
double const addedResHWM,
int const c)
{
out << OStreamWrapper::setw(maxLen - 2)
<< std::left
<< "| " + tag.substr(0,maxLen-4)
<< std::right
<< OStreamWrapper::setw(2)
<< " |"
<< OStreamWrapper::setw(columnWidth - 19)
<< c
<< OStreamWrapper::setw(2)
<< " |"
<< OStreamWrapper::setw(columnWidth - 8)
<< std::fixed
<< std::showpoint
<< int64(resMem)
<< OStreamWrapper::setw(2)
<< " |"
<< OStreamWrapper::setw(columnWidth - 6)
<< std::fixed
<< std::showpoint
<< int64(addedResMem)
<< OStreamWrapper::setw(2)
<< " |"
<< OStreamWrapper::setw(columnWidth - 2)
<< std::fixed
<< std::showpoint
<< int64(addedResHWM)
<< OStreamWrapper::setw(2)
<< " |"
<< std::endl;
}