using legacy librealsense in qtcreator and cmake - ubuntu-16.04

Question

I want to setup qt-creator for developing legacy librealsense in ubuntu16.04. I want to use CMake. I have librealsense installed on my system and the header files are in the "/usr/local/include" and the "librealsense.so" file is in the "/usr/local/lib". so I've created a simple CPP project with CMakeLists.txt and main.cpp files. my files are as follow:
main.cpp file:
#include <iostream>
#include <librealsense/rs.hpp>
int main()
{
rs::context ctx;
std::cout << "Hello World!" << std::endl;
return 0;
}
CMakeLists.txt file:
cmake_minimum_required(VERSION 2.8)
project(realsense_r200)
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)
find_library(librealsense REQUIRED)
add_executable(${PROJECT_NAME} "main.cpp")
target_link_libraries(${PROJECT_NAME} ${librealsense_LIBRARY})
target_include_directories(${PROJECT_NAME} PRIVATE ${librealsense_INCLUDE_DIR})
there are two problems:
find_library(), can't find the librealsense and in the CMake cache list, in front of librealsense, I get NOT_FOUND.
to solve the first problem I added the "librealsense.so" path manually in the cache list. so I have no errors in the generation of make files. but how can I set it up to find the path automatically?
when I try to build my project I have undefined reference errors to some methods as below:
CMakeFiles/realsense_r200.dir/main.cpp.o: In function `rs_apply_depth_control_preset(rs_device*, int)':
main.cpp:(.text+0x61d): undefined reference to `rs_set_device_options'
CMakeFiles/realsense_r200.dir/main.cpp.o: In function `rs_apply_ivcam_preset(rs_device*, rs_ivcam_preset)':
main.cpp:(.text+0x734): undefined reference to `rs_reset_device_options_to_default'
main.cpp:(.text+0x7d1): undefined reference to `rs_set_device_options'
main.cpp:(.text+0x869): undefined reference to `rs_set_device_options'
main.cpp:(.text+0x8ba): undefined reference to `rs_set_device_options'
CMakeFiles/realsense_r200.dir/main.cpp.o: In function `rs::error::error(rs_error*)':
main.cpp:(.text._ZN2rs5errorC2EP8rs_error[_ZN2rs5errorC5EP8rs_error]+0x2a): undefined reference to `rs_get_error_message'
main.cpp:(.text._ZN2rs5errorC2EP8rs_error[_ZN2rs5errorC5EP8rs_error]+0x74): undefined reference to `rs_get_failed_function'
main.cpp:(.text._ZN2rs5errorC2EP8rs_error[_ZN2rs5errorC5EP8rs_error]+0x9b): undefined reference to `rs_get_failed_function'
main.cpp:(.text._ZN2rs5errorC2EP8rs_error[_ZN2rs5errorC5EP8rs_error]+0x102): undefined reference to `rs_get_failed_args'
main.cpp:(.text._ZN2rs5errorC2EP8rs_error[_ZN2rs5errorC5EP8rs_error]+0x129): undefined reference to `rs_get_failed_args'
main.cpp:(.text._ZN2rs5errorC2EP8rs_error[_ZN2rs5errorC5EP8rs_error]+0x190): undefined reference to `rs_free_error'
CMakeFiles/realsense_r200.dir/main.cpp.o: In function `rs::context::context()':
main.cpp:(.text._ZN2rs7contextC2Ev[_ZN2rs7contextC5Ev]+0x30): undefined reference to `rs_create_context'
CMakeFiles/realsense_r200.dir/main.cpp.o: In function `rs::context::~context()':
main.cpp:(.text._ZN2rs7contextD2Ev[_ZN2rs7contextD5Ev]+0x1c): undefined reference to `rs_delete_context'
CMakeFiles/realsense_r200.dir/build.make:94: recipe for target 'realsense_r200' failed
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/realsense_r200.dir/all' failed
Makefile:83: recipe for target 'all' failed
collect2: error: ld returned 1 exit status
make[2]: *** [realsense_r200] Error 1
make[1]: *** [CMakeFiles/realsense_r200.dir/all] Error 2
make: *** [all] Error 2
18:32:02: The process "/usr/bin/cmake" exited with code 2.
Error while building/deploying project realsense_r200 (kit: Desktop)
When executing step "CMake Build"
as you see in the CMakeLists.txt file I've linked the "librealsense.so" file to the executable, why I get these errors and how can I solve it?
thanks for your help!!!
#
Edited Part
I changed my cmake file as below:
new CMake file:
cmake_minimum_required(VERSION 2.8)
project(realsense_r200)
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)
find_library(REALSENSE librealsense)
find_package(Threads)
add_executable(${PROJECT_NAME} "main.cpp")
target_link_libraries(${PROJECT_NAME} ${REALSENSE} ${CMAKE_THREAD_LIBS_INIT})
the undefined errors have gone, but I have new errors as below:
/usr/local/lib/librealsense.so: undefined reference to `std::thread::_State::~_State()#GLIBCXX_3.4.22'
/usr/local/lib/librealsense.so: undefined reference to `typeinfo for std::thread::_State#GLIBCXX_3.4.22'CMakeFiles/realsense_r200.dir/build.make:95: recipe for target 'realsense_r200' failed
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/realsense_r200.dir/all' failed
Makefile:83: recipe for target 'all' failed
/usr/local/lib/librealsense.so: undefined reference to `std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)())#GLIBCXX_3.4.22'
collect2: error: ld returned 1 exit status
make[2]: *** [realsense_r200] Error 1
make[1]: *** [CMakeFiles/realsense_r200.dir/all] Error 2
make: *** [all] Error 2
23:35:55: The process "/usr/bin/cmake" exited with code 2.
Error while building/deploying project realsense_r200 (kit: Desktop)
When executing step "CMake Build"