24

我一直在搞乱在我的一个项目中使用 RapidXML。一切都很顺利，直到我决定用它来写出 xml。我的代码或多或少如下：

//attempt to open the file for writing
std::ofstream file(fileName.c_str());
if (!file.is_open())
    return false; //the file didn't open

xml_document<> doc;
//creates the contents of the document...
//...
//...

//write the document out to the file
file << doc; //if I remove this line it compiles...but I kinda need this line to output to the file
file.close();

在编译时，我收到以下错误：

In file included from ../Engine/xmlfileloader.cpp:12:0:
../Engine/include/rapidxml_print.hpp: In instantiation of 'OutIt rapidxml::internal::print_node(OutIt, const rapidxml::xml_node<Ch>*, int, int) [with OutIt = std::ostream_iterator<char, char, std::char_traits<char> >; Ch = char]':
../Engine/include/rapidxml_print.hpp:390:57:   required from 'OutIt rapidxml::print(OutIt, const rapidxml::xml_node<Ch>&, int) [with OutIt = std::ostream_iterator<char, char, std::char_traits<char> >; Ch = char]'
../Engine/include/rapidxml_print.hpp:403:9:   required from 'std::basic_ostream<Ch>& rapidxml::print(std::basic_ostream<Ch>&, const rapidxml::xml_node<Ch>&, int) [with Ch = char]'
../Engine/include/rapidxml_print.hpp:414:31:   required from 'std::basic_ostream<Ch>& rapidxml::operator<<(std::basic_ostream<Ch>&, const rapidxml::xml_node<Ch>&) [with Ch = char]'
../Engine/xmlfileloader.cpp:400:13:   required from here
../Engine/include/rapidxml_print.hpp:115:17: error: 'print_children' was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation [-fpermissive]
../Engine/include/rapidxml_print.hpp:169:22: note: 'template<class OutIt, class Ch> OutIt rapidxml::internal::print_children(OutIt, const rapidxml::xml_node<Ch>*, int, int)' declared here, later in the translation unit
../Engine/include/rapidxml_print.hpp:120:17: error: 'print_element_node' was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation [-fpermissive]
../Engine/include/rapidxml_print.hpp:242:22: note: 'template<class OutIt, class Ch> OutIt rapidxml::internal::print_element_node(OutIt, const rapidxml::xml_node<Ch>*, int, int)' declared here, later in the translation unit
../Engine/include/rapidxml_print.hpp:125:17: error: 'print_data_node' was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation [-fpermissive]
../Engine/include/rapidxml_print.hpp:208:22: note: 'template<class OutIt, class Ch> OutIt rapidxml::internal::print_data_node(OutIt, const rapidxml::xml_node<Ch>*, int, int)' declared here, later in the translation unit
../Engine/include/rapidxml_print.hpp:130:17: error: 'print_cdata_node' was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation [-fpermissive]
../Engine/include/rapidxml_print.hpp:219:22: note: 'template<class OutIt, class Ch> OutIt rapidxml::internal::print_cdata_node(OutIt, const rapidxml::xml_node<Ch>*, int, int)' declared here, later in the translation unit
../Engine/include/rapidxml_print.hpp:135:17: error: 'print_declaration_node' was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation [-fpermissive]
../Engine/include/rapidxml_print.hpp:298:22: note: 'template<class OutIt, class Ch> OutIt rapidxml::internal::print_declaration_node(OutIt, const rapidxml::xml_node<Ch>*, int, int)' declared here, later in the translation unit
../Engine/include/rapidxml_print.hpp:140:17: error: 'print_comment_node' was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation [-fpermissive]
../Engine/include/rapidxml_print.hpp:321:22: note: 'template<class OutIt, class Ch> OutIt rapidxml::internal::print_comment_node(OutIt, const rapidxml::xml_node<Ch>*, int, int)' declared here, later in the translation unit
../Engine/include/rapidxml_print.hpp:145:17: error: 'print_doctype_node' was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation [-fpermissive]
../Engine/include/rapidxml_print.hpp:339:22: note: 'template<class OutIt, class Ch> OutIt rapidxml::internal::print_doctype_node(OutIt, const rapidxml::xml_node<Ch>*, int, int)' declared here, later in the translation unit
../Engine/include/rapidxml_print.hpp:150:17: error: 'print_pi_node' was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation [-fpermissive]
../Engine/include/rapidxml_print.hpp:361:22: note: 'template<class OutIt, class Ch> OutIt rapidxml::internal::print_pi_node(OutIt, const rapidxml::xml_node<Ch>*, int, int)' declared here, later in the translation unit

对我来说没有意义的是为什么它会以这种方式打破。查看rapidxml_print.hpp标题，我看到上面提到的所有函数都在 print_node 函数中引用。后来定义了print_children、print_element_node等函数，一看就ok了。我在这里做错了什么？

4

3 回答 3

66

对于那些来这里寻找相同问题的解决方案的人，我有一个解决方案。在“名称查找更改”下查看http://gcc.gnu.org/gcc-4.7/porting_to.html（根据 nm 的建议）后，我将 rapidxml_print.hpp 标头更改为在声明 print_node 函数之前具有以下权利（在我的文件中，我在第 104 行之后插入了这个）：

template<class OutIt, class Ch>
inline OutIt print_children(OutIt out, const xml_node<Ch> *node, int flags, int indent);

template<class OutIt, class Ch>
inline OutIt print_attributes(OutIt out, const xml_node<Ch> *node, int flags);

template<class OutIt, class Ch>
inline OutIt print_data_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);

template<class OutIt, class Ch>
inline OutIt print_cdata_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);

template<class OutIt, class Ch>
inline OutIt print_element_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);

template<class OutIt, class Ch>
inline OutIt print_declaration_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);

template<class OutIt, class Ch>
inline OutIt print_comment_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);

template<class OutIt, class Ch>
inline OutIt print_doctype_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);

template<class OutIt, class Ch>
inline OutIt print_pi_node(OutIt out, const xml_node<Ch> *node, int flags, int indent);

它现在可以很好地使用 GCC 编译，并带有一个警告，因为int flagsprint_attributes 函数中显然没有使用它。

于 2013-01-01T21:15:21.143 回答
4

如果您需要使用大于或等于 4.7 的 gcc 版本，并且您在构建期间正在克隆 rapidxml 存储库。

代替：

#include "rapidxml.hpp"
#include "rapidxml_print.hpp"

有了这个：

#include "rapidxml_ext.h"

rapidxml_ext.h：

#ifndef RAPIDXML_EXT_H_
#define RAPIDXML_EXT_H_
#include "rapidxml.hpp"
/* Adding declarations to make it compatible with gcc 4.7 and greater */
namespace rapidxml {
namespace internal {
    template <class OutIt, class Ch>
    inline OutIt print_children(OutIt out, const xml_node<Ch>* node, int flags, int indent);

template <class OutIt, class Ch>
inline OutIt print_attributes(OutIt out, const xml_node<Ch>* node, int flags);

template <class OutIt, class Ch>
inline OutIt print_data_node(OutIt out, const xml_node<Ch>* node, int flags, int indent);

template <class OutIt, class Ch>
inline OutIt print_cdata_node(OutIt out, const xml_node<Ch>* node, int flags, int indent);

template <class OutIt, class Ch>
inline OutIt print_element_node(OutIt out, const xml_node<Ch>* node, int flags, int indent);

template <class OutIt, class Ch>
inline OutIt print_declaration_node(OutIt out, const xml_node<Ch>* node, int flags, int indent);

template <class OutIt, class Ch>
inline OutIt print_comment_node(OutIt out, const xml_node<Ch>* node, int flags, int indent);

template <class OutIt, class Ch>
inline OutIt print_doctype_node(OutIt out, const xml_node<Ch>* node, int flags, int indent);

template <class OutIt, class Ch>
inline OutIt print_pi_node(OutIt out, const xml_node<Ch>* node, int flags, int indent);
}
}
#include "rapidxml_print.hpp"

#endif /* RAPIDXML_EXT_H_ */
于 2019-03-29T00:08:21.020 回答
0

为了消除 print_attributes 函数中未使用的标志，删除该函数原型中的标志字

template<class OutIt, class Ch>
inline OutIt print_attributes(OutIt out, const xml_node<Ch> *node, int);

并在其声明中

template<class OutIt, class Ch>
inline OutIt print_attributes(OutIt out, const xml_node<Ch> *node, int)
{
于 2016-12-21T14:17:00.390 回答