Question

类模板tee_filter和tee_device提供了两种分割输出序列的方法以便所有数据同时指向两个不同的位置。

我正在寻找一个完整的C ++示例，使用Boost tee输出到标准输出和“sample.txt”之类的文件。

Answer 1

基于John链接问题的帮助：

#include <boost/iostreams/tee.hpp>
#include <boost/iostreams/stream.hpp>
#include <fstream>
#include <iostream>

using std::ostream;
using std::ofstream;
using std::cout;

namespace bio = boost::iostreams;
using bio::tee_device;
using bio::stream;

int main()
{
    typedef tee_device<ostream, ofstream> TeeDevice;
    typedef stream<TeeDevice> TeeStream;
    ofstream ofs("sample.txt");
    TeeDevice my_tee(cout, ofs); 
    TeeStream my_split(my_tee);
    my_split << "Hello, World!\n";
    my_split.flush();
    my_split.close();
}

Answer 2

以下是使用tee_filter我当前用来开发Boost.Test输出的示例：

{ // init code, use static streams to keep them alive until test run process end

    using namespace boost::iostreams;
    static ofstream ofs("boost_test_output.log.xml"); // log file
    static tee_filter<ostream>  fileFilt(ofs); // tee all passed data to logfile

    // note derives from `boost::iostreams::output_filter`
    static text_xml_readability_filter xmlFilt; // filter all passed data, making the XML output readable

    static filtering_ostream filter; // master filter

    filter.push(fileFilt); // 1st, tee off any data to the file (raw boost XML)
    filter.push(xmlFilt);  // 2nd make the xml data stream readable (linebreaks, etc.)
    filter.push(cout);     // 3rd output the readable XML to cout

    boost::unit_test::unit_test_log.set_stream( filter );
}

C ++“hello world”Boost tee示例程序

2 个答案: