Is it possible to directly feed a QString into (e.g.) googletest's ADD_FAILURE() macro?

Question

I've already enhanced my googletest environment to handle a handful of Qt Types, like QString (for more details see this question).

inline void PrintTo(const QString& str, ::std::ostream* os)
{
    *os << "<" << qUtf8Printable(str) << ">";
}

This works fine for most gtest macros like EXPECT_EQ etc.

However when I try to directly pipe a QString into a e.g. ADD_FAILURE() macro the compiler complaints...

//...
ADD_FAILURE() << QString("Test!");
//...    

gtest-message.h(131): error C2679: Binary Operator "<<": Could not find an operator that accepts "const QString" (...)

Is there a way to enhance my gtest further to be able to directly use QStrings, or is there no way to avoid wrapping those QStrings in qUtf8Printable()?

To Clarify:
Writing ADD_FAILURE() << qUtf8Printable(QString("Test!")); works, as does ADD_FAILURE() << QString("Test!").toStdString();.
But it would be much nicer if those explicit conversions/calls could be avoided, e.g. by enabling ADD_FAILURE() to directly handle QString. (Code duplication is bad - even if this only is only one additional short function call to write each time, you can expect to repeat the construct across thousands of tests...)

Here an excerpt of the raw (untranslated) error message (the entire error message consists of 132 lines listing what the compiler could not match the function to)

2>c:\development\external\googletest\include\gtest\gtest-message.h(131): error C2679: Binärer Operator "<<": Es konnte kein Operator gefunden werden, der einen rechtsseitigen Operanden vom Typ "const QString" akzeptiert (oder keine geeignete Konvertierung möglich)  
2>  c:\program files (x86)\microsoft visual studio 14.0\vc\include\ostream(495): note: kann "std::basic_ostream<char,std::char_traits<char>> &std::basic_ostream<char,std::char_traits<char>>::operator <<(std::basic_streambuf<char,std::char_traits<char>> *)"  
2>  c:\program files (x86)\microsoft visual studio 14.0\vc\include\ostream(475): note: oder "std::basic_ostream<char,std::char_traits<char>> &std::basic_ostream<char,std::char_traits<char>>::operator <<(const void *)"  
2>  c:\program files (x86)\microsoft visual studio 14.0\vc\include\ostream(455): note: oder "std::basic_ostream<char,std::char_traits<char>> &std::basic_ostream<char,std::char_traits<char>>::operator <<(long double)" sein  
 ... **(snip)** ...  
2>  c:\program files (x86)\microsoft visual studio 14.0\vc\include\ostream(981): note: oder "std::basic_ostream<char,std::char_traits<char>> &std::operator <<<char,std::char_traits<char>,T>(std::basic_ostream<char,std::char_traits<char>> &&,const _Ty &)"  
2>          with  
2>          [  
2>              T=QString,  
2>              _Ty=QString  
2>          ]  
2>  c:\program files (x86)\microsoft visual studio 14.0\vc\include\ostream(1019): note: oder "std::basic_ostream<char,std::char_traits<char>> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<char,std::char_traits<char>> &,const std::error_code &)"  
2>  c:\development\external\googletest\include\gtest\gtest-message.h(131): note: bei Anpassung der Argumentliste "(std::stringstream, const QString)"  
2>  c:\development\test\src\codetest.cpp(390): note: Siehe Verweis auf die Instanziierung der gerade kompilierten Funktions-template "testing::Message &testing::Message::operator <<<QString>(const T &)".  
2>          with  
2>          [  
2>              T=QString  
2>          ] 

Answer 1

QString does not provide a related non member for streaming insertion, that is the cause of your problem. (the compiler does not find any binary operator function accepting a const QString& as parameter)

See this Question that is related to your problem : Operator << for QString

I guess that you have in your Qt config file

 DEFINES += QT_NO_CAST_TO_ASCII 

that prevents the compiler for converting your QString to a char*

In this case you can write somewhere this global operator

std::ostream & operator<<(std::ostream & stream, const QString & str)
{
    const QByteArray data = str.toUtf8();
    stream << std::string(data.constData(), data.size());
    return stream;
}