如何将标准输出消息重定向到FLTK的Fl_Multiline_Output？

#include <iostream>
#include <sstream>
#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Multiline_Output.H>

class OutputRedirect : public std::ostream {
public:
    OutputRedirect(Fl_Multiline_Output *output) : output_(output) {}

    template <typename T>
    OutputRedirect &operator<<(const T &value) {
        std::ostringstream oss;
        oss << value;
        output_->value(oss.str().c_str());
        output_->redraw();
        return *this;
    }

private:
    Fl_Multiline_Output *output_;
};

int main(int argc, char *argv[]) {
    Fl_Window *window = new Fl_Window(400, 300, "Output Window");
    Fl_Multiline_Output *output = new Fl_Multiline_Output(10, 10, 380, 280);

    OutputRedirect redirect(output);
    std::cout.rdbuf(&redirect);

    std::cout << "Hello, FLTK!" << std::endl;

    window->end();
    window->show(argc, argv);
    return Fl::run();
}