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How to define insert operators for all C ++ IOStream manipulators?

All,

Why the following code cannot be compiled for 'std :: endl', but is it suitable for all other inserted types?

#include <sstream> // ostringstream

/// @brief A class that does streamed, formatted output via 'operator<<'.
class My_Stream
{
public:
    /// @brief A member method that manipulates the underlying stream.
    void foo()
    {
        m_oss << "foo_was_here; ";
    }

private:
    /// @brief The underlying stream.
    std::ostringstream m_oss;

    /// @brief 'operator<<' is a friend.
    template< typename T >
    friend My_Stream& operator<<( My_Stream& a_r_my_stream,
                                  const T& a_r_value );
};

/// @brief A manipulator that calls a class method.
My_Stream& manipulator_foo( My_Stream& a_r_my_stream )
{
    a_r_my_stream.foo();
    return a_r_my_stream;
}

/// @brief The generic insertion operator.
template< typename T >
My_Stream& operator<<( My_Stream& a_r_my_stream,
                       const T& a_r_value )
{
    a_r_my_stream.m_oss << a_r_value;
    return a_r_my_stream;
}

/// @brief Define an iostream-like manipulator for my-stream.
typedef My_Stream& ( * my_stream_manipulator ) ( My_Stream& );

/// @brief The specialized 'my_stream_manipulator' insertion operator.
template<>
My_Stream& operator<<( My_Stream& a_r_my_stream,
                       const my_stream_manipulator& a_r_manipulator )
{
    return a_r_manipulator( a_r_my_stream );
}

int main( int argc, char* argv[] )
{
    My_Stream my_stream;

    my_stream << 'c'; // char
    my_stream << "string"; // c-string
    my_stream << 1u; // unsigned int
    my_stream << -1; // signed int
    my_stream << 5.3f; // float
    my_stream << -23.345; // double
    my_stream << std::boolalpha; // std::ios_base manipulator
    my_stream << std::endl; // std::ostream manipulator
    my_stream << manipulator_foo; // my_stream manipulator

    return 0;
}

I get the following g ++ 4.5 error:

willo: ~ / test_cpp $ g ++ -Wall test_overloaded_insertion_manipulators.cpp test_overloaded_insertion_manipulators.cpp: In the function 'int main (int, char **): test_overloaded_insertion_manipulators.cpp: 60: error: no match for' operator <<<in 'my_stream <standard :: cps

I expect the code to instantiate the '<<operator for std :: endl, as well as for the primitives, std :: ios_base and my custom manipulator.

light-API IOStream, IOStream, .

+5
2

endl :

template <class charT, class traits>
basic_ostream<charT,traits>& endl(basic_ostream<charT,traits>& os);

, . ( ) . operator<< , , , , endl .

, , boolalpha:

ios_base& boolalpha(ios_base& str);

, .

endl basic_ostream, operator<< -, ; :

basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>& (*pf)(basic_ostream<charT,traits>&));

, stream << endl charT traits this (.. ), , - endl. .

+7

.

:

// Note: Untested (don't have a compiler here).
template <class charT, class Traits>
friend My_Stream& operator<<( My_Stream&, std::basic_ostream<charT, Traits>& (*)(std::basic_ostream<charT, Traits>&));

:

template <class charT, class Traits>
My_Stream& operator<<( My_Stream& stream, std::basic_ostream<charT, Traits>& (*manip)(std::basic_ostream<charT, Traits>&))
{
    (*manip)(stream.m_oss);
    return stream;
}
+2

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