Class LogStreamConsumer

quickstart/common/logging.h:133–181

\class LogStreamConsumer \brief Convenience object used to facilitate use of C++ stream syntax when logging messages. Order of base classes is LogStreamConsumerBase and then std::ostream. This is because the LogStreamConsumerBase class is used to initialize the LogStreamConsumerBuffer member field in LogStreamConsumer and then the address of the buffer is passed to std::ostream. This is necessary

//!  Please do not change the order of the parent classes.
//!
class LogStreamConsumer : protected LogStreamConsumerBase, public std::ostream
{
public:
    //! \brief Creates a LogStreamConsumer which logs messages with level severity.
    //!  Reportable severity determines if the messages are severe enough to be logged.
    LogStreamConsumer(Severity reportableSeverity, Severity severity)
        : LogStreamConsumerBase(severityOstream(severity), severityPrefix(severity), severity <= reportableSeverity)
        , std::ostream(&mBuffer) // links the stream buffer with the stream
        , mShouldLog(severity <= reportableSeverity)
        , mSeverity(severity)
    {
    }

    LogStreamConsumer(LogStreamConsumer&& other)
        : LogStreamConsumerBase(severityOstream(other.mSeverity), severityPrefix(other.mSeverity), other.mShouldLog)
        , std::ostream(&mBuffer) // links the stream buffer with the stream
        , mShouldLog(other.mShouldLog)
        , mSeverity(other.mSeverity)
    {
    }

    void setReportableSeverity(Severity reportableSeverity)
    {
        mShouldLog = mSeverity <= reportableSeverity;
        mBuffer.setShouldLog(mShouldLog);
    }

private:
    static std::ostream& severityOstream(Severity severity)
    {
        return severity >= Severity::kINFO ? std::cout : std::cerr;
    }

    static std::string severityPrefix(Severity severity)
    {
        switch (severity)
        {
        case Severity::kINTERNAL_ERROR: return "[F] ";
        case Severity::kERROR: return "[E] ";
        case Severity::kWARNING: return "[W] ";
        case Severity::kINFO: return "[I] ";
        case Severity::kVERBOSE: return "[V] ";
        default: assert(0); return "";
        }
    }

    bool mShouldLog;
    Severity mSeverity;
};

//! \class Logger
//!