正在添加 boost::any in a boost::p roperty_tree 可能
Is Adding boost::any in a boost::property_tree Possible?
我正在尝试将 boost::any 类型存储到提升属性树中。下面是一些可运行的示例:
#include <string>
#include <vector>
#include <sstream>
#include <iostream>
#include <sys/types.h>
#include <boost/any.hpp>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/json_parser.hpp>
int main()
{
boost::property_tree::ptree pTree_Root;
pTree_Root.put("sigRoot.property1", "value1");
pTree_Root.put("sigRoot.property2", "value2");
pTree_Root.put("sigRoot.property3", "value3");
std::vector<std::string> vecString;
for(int i = 0; i <= 5; i++) {
vecString.push_back("somestring");
}
boost::any anyVar = vecString;
pTree_Root.put("sigRoot.property4", anyVar);
std::stringstream ss;
boost::property_tree::json_parser::write_json(ss, pTree_Root);
std::string jsonString = ss.str();
jsonString.erase(std::remove(jsonString.begin(), jsonString.end(), 'n'), jsonString.end());
std::cout << jsonString << std::endl;
return 0;
}
这不起作用,可能出于同样的原因 boost::any 不可序列化。但是我看到我可以查询anyVar.type()
,但我不知道可以用它做什么。是否可以以某种方式使用 auto
或其他东西将数据添加到属性树中,而无需在此处显式编码固定数量的已知类型?C++11/C++0x 方法也是受欢迎的。
这是我得到的错误:
In file included from /usr/include/boost/property_tree/ptree.hpp:17:0,
from pTreeTest.cpp:8:
/usr/include/boost/property_tree/stream_translator.hpp: In static member function ‘static void boost::property_tree::customize_stream<Ch, Traits, E, Enabler>::insert(std::basic_ostream<_Ch, _Tr>&, const E&) [with Ch = char, Traits = std::char_traits<char>, E = boost::any, Enabler = void]’:
/usr/include/boost/property_tree/stream_translator.hpp:199:13: instantiated from ‘boost::optional<std::basic_string<Ch, Traits, Alloc> > boost::property_tree::stream_translator<Ch, Traits, Alloc, E>::put_value(const E&) [with Ch = char, Traits = std::char_traits<char>, Alloc = std::allocator<char>, E = boost::any]’
/usr/include/boost/property_tree/detail/ptree_implementation.hpp:795:54: instantiated from ‘void boost::property_tree::basic_ptree<Key, Data, KeyCompare>::put_value(const Type&, Translator) [with Type = boost::any, Translator = boost::property_tree::stream_translator<char, std::char_traits<char>, std::allocator<char>, boost::any>, Key = std::basic_string<char>, Data = std::basic_string<char>, KeyCompare = std::less<std::basic_string<char> >]’
/usr/include/boost/property_tree/detail/ptree_implementation.hpp:817:13: instantiated from ‘boost::property_tree::basic_ptree<K, D, C>& boost::property_tree::basic_ptree<Key, Data, KeyCompare>::put(const path_type&, const Type&, Translator) [with Type = boost::any, Translator = boost::property_tree::stream_translator<char, std::char_traits<char>, std::allocator<char>, boost::any>, Key = std::basic_string<char>, Data = std::basic_string<char>, KeyCompare = std::less<std::basic_string<char> >, boost::property_tree::basic_ptree<Key, Data, KeyCompare>::path_type = boost::property_tree::string_path<std::basic_string<char>, boost::property_tree::id_translator<std::basic_string<char> > >]’
/usr/include/boost/property_tree/detail/ptree_implementation.hpp:832:72: instantiated from ‘boost::property_tree::basic_ptree<K, D, C>& boost::property_tree::basic_ptree<Key, Data, KeyCompare>::put(const path_type&, const Type&) [with Type = boost::any, Key = std::basic_string<char>, Data = std::basic_string<char>, KeyCompare = std::less<std::basic_string<char> >, boost::property_tree::basic_ptree<Key, Data, KeyCompare>::path_type = boost::property_tree::string_path<std::basic_string<char>, boost::property_tree::id_translator<std::basic_string<char> > >]’
pTreeTest.cpp:26:47: instantiated from here
/usr/include/boost/property_tree/stream_translator.hpp:33:13: error: cannot bind ‘std::basic_ostream<char>’ lvalue to ‘std::basic_ostream<char>&&’
/usr/include/c++/4.6/ostream:581:5: error: initializing argument 1 of ‘std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&&, const _Tp&) [with _CharT = char, _Traits = std::char_traits<char>, _Tp = boost::any]’
No. boost::any
没有operator <<
.您不能在 property_tree
中使用any
。 anyVar.type()
返回std::typeinfo
,此类提供有关类型的runtime
信息。
template<typename Type, typename Translator>
self_type & put(const path_type & path, const Type & value, Translator tr);
将给定路径处的节点值设置为提供的值,并转换为树的数据类型。如果节点不存在,则创建该节点,包括其所有缺少的父节点。
您可以创建Translator
并将其传递给函数 put,因为ptree
确实basic_ptree<std::string, std::string>
您的翻译人员应该将您的any
转换为 string
。
翻译器的简单示例
struct SimpleTranslator
{
public:
boost::optional<std::string> put_value(const boost::any& value)
{
if (value.type() == typeid(std::vector<std::string>))
{
std::stringstream ss;
std::vector<std::string> vec = boost::any_cast<std::vector<std::string>>(value);
std::copy(vec.begin(), vec.end(), std::ostream_iterator<std::string>(ss));
return ss.str();
}
return boost::optional<std::string>();
}
};
http://liveworkspace.org/code/275820c1becfb63deda4e4eed8524833
相关文章:
- 理解boost::asio-async_read在无需读取内容时的行为
- boost::进程间消息队列引发错误
- 如何运行位于boost/libs/python/example/tutorial目录中的hello.cpp和Jamfil
- cmake如何在fedora工作站中找到boost静态库包
- CMake项目Boost库错误:Boost/config/compiler/gcc.hpp:165:10:致命错误:cs
- Boost Graph Library,修复节点大小
- 什么是"#include <boost/functional/hash.hpp> "?
- 基于boost的程序的静态链接——zlib问题
- C++:如何在CLion IDE中安装Boost
- C++Boost Asio Pool线程,带有lambda函数和传递引用变量
- 如何在boost beast http请求中设置http头
- Boost Spirit,获取迭代器内部语义动作
- boost::asio::steady_timer()与sleep()我应该使用哪一个
- boost::asio如何生成多个协同程序,然后加入它们
- 当我尝试使用 sstream 和分面将 Boost Time_duration转换为字符串时,我没有得到所需的格式
- Visual Studio(或任何其他工具)能否将地址解释为调用堆栈(boost上下文)的开头
- 如何使用boost::具有嵌套结构和最小代码更改的序列化
- 使用Boost Interprocess创建托管共享内存需要很长时间
- Boost::posix_time::ptime舍入到给定的分钟数
- 任何用于 boost::p roperty 树的标准库实现