Compilation error

[karantai]

While compiling, this error is created. Can you help me with that?

-- FLANN found (include: /usr/include, lib: /usr/lib/x86_64-linux-gnu/libflann_cpp.so) -- OpenNI found (version: 1.5.4.0, include: /usr/include/ni, lib: /usr/lib/libOpenNI.so;libusb::libusb) -- OpenNI2 found (version: 2.2.0.33, include: /usr/include/openni2, lib: /usr/lib/x86_64-linux-gnu/libOpenNI2.so;libusb::libusb) -- Could NOT find Pcap (missing: PCAP_LIBRARIES PCAP_INCLUDE_DIRS) ** WARNING ** io features related to pcap will be disabled -- OpenNI found (version: 1.5.4.0, include: /usr/include/ni, lib: /usr/lib/libOpenNI.so;libusb::libusb) -- OpenNI2 found (version: 2.2.0.33, include: /usr/include/openni2, lib: /usr/lib/x86_64-linux-gnu/libOpenNI2.so;libusb::libusb) -- Found Qhull version 8.0.2 -- OpenNI found (version: 1.5.4.0, include: /usr/include/ni, lib: /usr/lib/libOpenNI.so;libusb::libusb) -- looking for PCL_COMMON -- looking for PCL_KDTREE -- looking for PCL_OCTREE -- looking for PCL_SEARCH -- looking for PCL_SAMPLE_CONSENSUS -- looking for PCL_FILTERS -- looking for PCL_2D -- looking for PCL_GEOMETRY -- looking for PCL_IO -- looking for PCL_FEATURES -- looking for PCL_ML -- looking for PCL_SEGMENTATION -- looking for PCL_VISUALIZATION -- looking for PCL_SURFACE -- looking for PCL_REGISTRATION -- looking for PCL_KEYPOINTS -- looking for PCL_TRACKING -- looking for PCL_RECOGNITION -- looking for PCL_STEREO -- looking for PCL_APPS -- looking for PCL_OUTOFCORE -- looking for PCL_PEOPLE -- Configuring done -- Generating done -- Build files have been written to: /home/johnny/3d_line_detection/build make[1]: Entering directory '/home/johnny/3d_line_detection/build' make[2]: Entering directory '/home/johnny/3d_line_detection/build' make[3]: Entering directory '/home/johnny/3d_line_detection/build' Consolidate compiler generated dependencies of target 3d_line_detection make[3]: Leaving directory '/home/johnny/3d_line_detection/build' make[3]: Entering directory '/home/johnny/3d_line_detection/build' [ 50%] Building CXX object src/CMakeFiles/3d_line_detection.dir/Sphere.cpp.o /home/johnny/3d_line_detection/src/Sphere.cpp: In member function ‘void geometry::Sphere::subdivide()’: /home/johnny/3d_line_detection/src/Sphere.cpp:66:29: error: ‘string’ is not a member of ‘std’ 66 | std::unordered_map<std::string, int> newVerticesMap; | ^~~~~~ /home/johnny/3d_line_detection/src/Sphere.cpp:13:1: note: ‘std::string’ is defined in header ‘<string>’; did you forget to ‘#include <string>’? 12 | #include <3d_line_detection/Sphere.hpp> +++ |+#include <string> 13 | /home/johnny/3d_line_detection/src/Sphere.cpp:66:40: error: template argument 1 is invalid 66 | std::unordered_map<std::string, int> newVerticesMap; | ^ /home/johnny/3d_line_detection/src/Sphere.cpp:66:40: error: template argument 3 is invalid /home/johnny/3d_line_detection/src/Sphere.cpp:66:40: error: template argument 4 is invalid /home/johnny/3d_line_detection/src/Sphere.cpp:66:40: error: template argument 5 is invalid /home/johnny/3d_line_detection/src/Sphere.cpp:78:22: error: ‘string’ is not a member of ‘std’ 78 | std::string newVertexLabel = std::to_string(curTriangle[i]) + "_" + std::to_string(curTriangle[j]); | ^~~~~~ /home/johnny/3d_line_detection/src/Sphere.cpp:78:22: note: ‘std::string’ is defined in header ‘<string>’; did you forget to ‘#include <string>’? /home/johnny/3d_line_detection/src/Sphere.cpp:81:42: error: request for member ‘find’ in ‘newVerticesMap’, which is of non-class type ‘int’ 81 | auto it = newVerticesMap.find(newVertexLabel); | ^~~~ /home/johnny/3d_line_detection/src/Sphere.cpp:81:47: error: ‘newVertexLabel’ was not declared in this scope; did you mean ‘newVertexIdx’? 81 | auto it = newVerticesMap.find(newVertexLabel); | ^~~~~~~~~~~~~~ | newVertexIdx /home/johnny/3d_line_detection/src/Sphere.cpp:82:42: error: request for member ‘end’ in ‘newVerticesMap’, which is of non-class type ‘int’ 82 | if (it == newVerticesMap.end()) { | ^~~ /home/johnny/3d_line_detection/src/Sphere.cpp:86:36: error: request for member ‘insert’ in ‘newVerticesMap’, which is of non-class type ‘int’ 86 | newVerticesMap.insert(std::make_pair(newVertexLabel, newVertexIdx)); | ^~~~~~ make[3]: *** [src/CMakeFiles/3d_line_detection.dir/build.make:76: src/CMakeFiles/3d_line_detection.dir/Sphere.cpp.o] Error 1 make[3]: Leaving directory '/home/johnny/3d_line_detection/build' make[2]: *** [CMakeFiles/Makefile2:98: src/CMakeFiles/3d_line_detection.dir/all] Error 2 make[2]: Leaving directory '/home/johnny/3d_line_detection/build' make[1]: *** [Makefile:91: all] Error 2 make[1]: Leaving directory '/home/johnny/3d_line_detection/build' make: *** [Makefile:7: default] Error 2