boost::property_tree::ptree and UTF-8 with BOM

Question

boost:：property_tree：：ptree不能处理使用UTF-8和BOM的文件吗？

#include <boost/filesystem.hpp>
#include <boost/property_tree/ini_parser.hpp>
#include <cstdlib>
#include <iostream>
int main()
{
    try
    {
        boost::filesystem::path path("helper.ini");
        boost::property_tree::ptree pt;
        boost::property_tree::read_ini(path.string(), pt);
        const std::string foo = pt.get<std::string>("foo");
        std::cout << foo << 'n';
    }
    catch (const boost::property_tree::ini_parser_error& e)
    {
        std::cerr << "An error occurred while reading config file: " << e.what() << 'n';
        return EXIT_FAILURE;
    }
    catch (const boost::property_tree::ptree_bad_data& e)
    {
        std::cerr << "An error occurred while getting options from config file: " << e.what() << 'n';
        return EXIT_FAILURE;
    }
    catch (const boost::property_tree::ptree_bad_path& e)
    {
        std::cerr << "An error occurred while getting options from config file: " << e.what() << 'n';
        return EXIT_FAILURE;
    }
    catch (...)
    {
        std::cerr << "Unknown error n";
        return EXIT_FAILURE;
    }
}

helper.ini

foo=str

输出

从配置文件获取选项时出错：没有这样的节点（foo）

我能用它做什么？是否在读取之前手动从文件中删除BOM？

提升1.53

Answer 1

我用它跳过BOM字符：

    boost::property_tree::ptree pt;
    std::ifstream file("file.ini", std::ios::in);
    if (file.is_open())
    {
        //skip BOM
        unsigned char buffer[8];
        buffer[0] = 255;
        while (file.good() && buffer[0] > 127)
            file.read((char *)buffer, 1);
        std::fpos_t pos = file.tellg();
        if (pos > 0)
            file.seekg(pos - 1);
        //parse rest stream
        boost::property_tree::ini_parser::read_ini(file, pt);
        file.close();
    }

Answer 2

1. 是的，最简单的选择是检查文件是否以BOM开头并将其删除

2. 你可以针对boost（可能应该）提交一个错误

3. 只要找到BOM，就可以使用boost:：iostums过滤器从输入流中删除BOM：

   • 筛选器使用情况
   • 滤波器概念
   • 输入过滤器概念，带有可适用于删除BOM的示例