c++ - boost std::vector <double>的自定义验证器

我为std::vector<double>编写了以下自定义验证器。

typedef vector<double> coordinate;
void validate(boost::any& v,
  const vector<string>& values,
  coordinate*, int) {
  std::cout << "Custom validator called\n";
  coordinate c;
  vector<double> dvalues;
  for(vector<string>::const_iterator it = values.begin();
    it != values.end();
    ++it) {
    stringstream ss(*it);
    copy(istream_iterator<double>(ss), istream_iterator<double>(),
      back_inserter(dvalues));
    if(!ss.eof()) {
      std::cerr << "SS EOF\n";
      throw po::invalid_option_value("Invalid coordinate specification sseof");
    }
  }
  if(dvalues.size() != 2) {
    std::cerr << "dvalues size\n";
    throw po::invalid_option_value("Invalid coordinate specification dvalues size");
  }
  c.push_back(dvalues[0]);
  c.push_back(dvalues[1]);
  v = c;
}

我以以下方式添加选项:

coordinate c;
// Setup options.
po::options_description desc("Options");
desc.add_options()
  ("instruments.prop", po::value<coordinate>( &c )->multitoken(),
   "plugin names" );

该程序根本没有使用自定义验证器。如果正在使用我的验证器，我没有收到应该打出的消息“Custom Customized named”。相反，我得到这个错误:



我的配置文件如下所示:

[仪器]
Prop = 1 2.9

关于如何从配置文件中解析多个参数而无需像这样在单独的行中编写它们的任何想法:

[仪器]
Prop = 1
Prop = 2.9

最佳答案

您将改为编写自定义转换:

Live On Coliru

#include <boost/program_options.hpp>
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <fstream>
#include <iostream>

namespace po = boost::program_options;
typedef std::vector<double> coordinate;

int main() {
    coordinate c;

    // Setup options.
    po::options_description desc("Options");
    desc.add_options()
        ("instruments.prop", po::value<std::string>()->multitoken()->notifier([&c](std::string const& v) {
             auto it = boost::make_split_iterator(v, boost::token_finder(boost::algorithm::is_any_of(" ,")));
             std::transform(it, {}, back_inserter(c), [](auto& s) {
                        return boost::lexical_cast<double>(s);
                     });
         }),
         "plugin names" );

    std::ifstream ifs("input.txt");
    po::variables_map vm;
    store(po::parse_config_file(ifs, desc, false), vm);
    po::notify(vm);

    std::copy(c.begin(), c.end(), std::ostream_iterator<double>(std::cout << "c: ", " "));
    std::cout << "\n";
}

版画

c: 1 2.9

关于c++ - boost std::vector <double>的自定义验证器，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/43512200/