Question

我正在Ubuntu 16.04上使用ROS和C ++进行小组项目。一切正常，直到两周前我收到此错误消息突如其来：

In file included from /usr/include/c++/5/cstring:42:0,
         from /usr/include/boost/math/special_functions/detail/fp_traits.hpp:23,
         from /usr/include/boost/math/special_functions/fpclassify.hpp:20,
         from /usr/include/boost/math/special_functions/round.hpp:16,
         from /opt/ros/kinetic/include/ros/time.h:58,
         from /opt/ros/kinetic/include/ros/ros.h:38,
         from /home/benjamin/Documents/bob_ws/src/tutorial/hello_world/src/hello_world.cpp:1:
/usr/include/string.h: In function ‘size_t strlen(const char*)’:
/usr/include/string.h:395:6: error: ‘cout’ was not declared in this scope
      cout << *__s;
      ^
/usr/include/string.h:395:6: note: suggested alternative:
In file included from /opt/ros/kinetic/include/ros/time.h:54:0,
         from /opt/ros/kinetic/include/ros/ros.h:38,
         from /home/benjamin/Documents/bob_ws/src/tutorial/hello_world/src/hello_world.cpp:1:
/usr/include/c++/5/iostream:61:18: note:   ‘std::cout’
   extern ostream cout;  /// Linked to standard output
          ^
In file included from /usr/include/features.h:367:0,
         from /usr/include/stdlib.h:24,
         from /opt/ros/kinetic/include/ros/platform.h:53,
         from /opt/ros/kinetic/include/ros/time.h:53,
         from /opt/ros/kinetic/include/ros/ros.h:38,
         from /home/benjamin/Documents/bob_ws/src/tutorial/hello_world/src/hello_world.cpp:1:
/usr/include/string.h:396:6: error: expected primary-expression before ‘)’ token
      __THROW __attribute_pure__ __nonnull ((1));

作为C ++和ROS的新手，我首先想到的是，我因安装/删除了一些软件包而陷入困境。所以我尝试重新安装整个ros框架。没用，所以我写了一些程序（我认为）表明了我的问题所在。我不能包含<cstring>：

#include <cstring>

int main(int argc, char** argv)
{
  return 0;
}

使用g++ -Wall a.cpp -o atest进行编译时，我得到了2500 row error message。

现在，我认为cstring可能有一点问题，但是可惜我不知道如何解决它。我的谷歌搜索表明locate cstring | grep include可能是有趣的：

/usr/include/boost/compatibility/cpp_c_headers/cstring
/usr/include/boost/python/docstring_options.hpp
/usr/include/boost/test/utils/basic_cstring
/usr/include/boost/test/utils/basic_cstring/basic_cstring.hpp
/usr/include/boost/test/utils/basic_cstring/basic_cstring_fwd.hpp
/usr/include/boost/test/utils/basic_cstring/bcs_char_traits.hpp
/usr/include/boost/test/utils/basic_cstring/compare.hpp
/usr/include/boost/test/utils/basic_cstring/io.hpp
/usr/include/c++/4.8/cstring
/usr/include/c++/5/cstring
/usr/include/qt4/Qt/q3cstring.h
/usr/include/qt4/Qt3Support/q3cstring.h

安装两个版本的C ++可能是一个问题吗？

我即将设置系统从头开始，所以你们是我的最后希望。

Answer 1

由于@molbdnilo和@Konrad Rudolph，我发现我的ItemWriter（是C头文件）以某种方式试图导入/usr/include/string.h（这是c ++库）。在工作/usr/include/c++/5/iostream的vim差异之后，我删除了唯一的区别，只是iostream的include语句。

按照@digitalarbeiter的建议，手动更改此类文件中的某些代码通常是个坏主意，因此我重新安装了string.h

libc6-dev

它仍然有效。

我仍然不知道这怎么发生。该文件在4月进行了编辑，该错误在10月发生。无论如何，要感谢所有帮助者！

导入cstring失败：include <cstring>错误

1 个答案: