output.h

Go to the documentation of this file.

#ifndef FPMAS_OUTPUT_API_H
#define FPMAS_OUTPUT_API_H
 
#include "fpmas/api/scheduler/scheduler.h"
 
namespace fpmas { namespace api { namespace io {
 
    class Output {
        public:
            virtual void dump() = 0;
            virtual const scheduler::Job& job() = 0;
 
            virtual ~Output() {}
    };
 
    /*
     * Note: operator<< wrappers return std::ostream& instead of OutputStream&.
     * This does not make much difference in terms of user experience, but is
     * useful in the case of the DynamicFileOutput, where get() systematically
     * reopens the file, what discard content if openmode is out.
     * So for example, if OutputStream& is returned:
     * ```
     * dynamic_file_output << "hello" << "world";
     * ```
     * would print "world" to the file, since the second << operator call
     * destroys the file.
     * But, if std::ostream& is returned, only the first operator destroys the
     * file so "helloworld" is printed.
     *
     * However, in the following example:
     * ```
     * dynamic_file_output << "hello";
     * dynamic_file_output << "world";
     * ```
     * The file contains "world" since it is destroyed at the second call, what
     * is however a relatively consistent behavior.
     */
    struct OutputStream {
        virtual std::ostream& get() = 0;
 
        std::ostream& operator<<(std::ostream& (*func)(std::ostream&)) {
            return this->get() << func;
        }
 
        virtual ~OutputStream() {}
    };
 
    template<typename T>
        std::ostream& operator<<(OutputStream& output, const T& data) {
            return output.get() << data;
        }
 
    template<typename T>
        using Watcher = std::function<T()>;
}}}
#endif