CMake can't find stdc++11 after Xcode 10 update - c++

Question

I have a CMake project using SFML which was working fine but after updating to Xcode 10, all of the compiler files that CMake looks for can't be found.
clang: warning: libstdc++ is deprecated; move to libc++
I'm not sure how to move to the different lib source.
I've tried using set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=libc++") to use the flag.
It also tells me: Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -- broken. I can run the g++/c++ commands fine in the terminal. I assume they are being looked for in the same spot.
CMake file I'm trying to compile with. Its the SFML one:
SFML CMake
Full Error Message:
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -- broken
CMake Error at /Applications/CMake.app/Contents/share/cmake-3.7/Modules/CMakeTestCXXCompiler.cmake:44 (message):
The C++ compiler
"/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++"
is not able to compile a simple test program.
It fails with the following output:
Change Dir: /Users/DSchana/Documents/Libraries/SFML/build/CMakeFiles/CMakeTmp
Run Build Command:"/usr/bin/make" "cmTC_af3d5/fast"
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f
CMakeFiles/cmTC_af3d5.dir/build.make CMakeFiles/cmTC_af3d5.dir/build
Building CXX object CMakeFiles/cmTC_af3d5.dir/testCXXCompiler.cxx.o
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++
-arch x86_64 -isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.07.sdk
-mmacosx-version-min=10.7 -o
CMakeFiles/cmTC_af3d5.dir/testCXXCompiler.cxx.o -c
/Users/DSchana/Documents/Libraries/SFML/build/CMakeFiles/CMakeTmp/testCXXCompiler.cxx
warning: include path for stdlibc++ headers not found; pass '-std=libc++'
on the command line to use the libc++ standard library instead
[-Wstdlibcxx-not-found]
1 warning generated.
Linking CXX executable cmTC_af3d5
/Applications/CMake.app/Contents/bin/cmake -E cmake_link_script
CMakeFiles/cmTC_af3d5.dir/link.txt --verbose=1
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++
-arch x86_64 -isysroot
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.07.sdk
-mmacosx-version-min=10.7 -Wl,-search_paths_first
-Wl,-headerpad_max_install_names
CMakeFiles/cmTC_af3d5.dir/testCXXCompiler.cxx.o -o cmTC_af3d5
clang: warning: libstdc++ is deprecated; move to libc++ with a minimum
deployment target of OS X 10.9 [-Wdeprecated]
ld: library not found for -lstdc++
clang: error: linker command failed with exit code 1 (use -v to see
invocation)
make[1]: *** [cmTC_af3d5] Error 1
make: *** [cmTC_af3d5/fast] Error 2
CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
CMakeLists.txt:47 (project)
-- Configuring incomplete, errors occurred!

Answer 1

Ok. Turns out I just needed to add set(CMAKE_CXX_FLAGS "-stdlib=libc++") to my CMakeLists.txt