title: Error with array.h headers
body: <p>I use CLion and I have this simple code:</p>
  
  <pre><code>#include &lt;array&gt;
  
  int main() {
  
      std::array&lt;std::uint64_t, 3&gt; arr;
      return 0;
  }
  </code></pre>
  
  <p>In my <code>CMakeLists.txt</code> I tried all the compiler flags from c++11/gnu++11 to c++17/gnu++17, but I keep getting this error when trying to build the code above</p>
  
  <pre><code>/pathToCLion/clion-2018.1.2/bin/cmake/bin/cmake --build 
  
  /pathToCLionProject/my_project/cmake-build-default --target my_project -- -j 2
  /pathToCLion/clion-2018.1.2/bin/cmake/bin/cmake -H/pathToCLionProject/my_project -B/pathToCLionProject/my_project/cmake-build-default --check-build-system CMakeFiles/Makefile.cmake 0
  /usr/bin/gmake -f CMakeFiles/Makefile2 my_project
  gmake[1]: Entering directory '/pathToCLionProject/my_project/cmake-build-default'
  /pathToCLion/clion-2018.1.2/bin/cmake/bin/cmake -H/pathToCLionProject/my_project -B/pathToCLionProject/my_project/cmake-build-default --check-build-system CMakeFiles/Makefile.cmake 0
  /pathToCLion/clion-2018.1.2/bin/cmake/bin/cmake -E cmake_progress_start /pathToCLionProject/my_project/cmake-build-default/CMakeFiles 2
  /usr/bin/gmake -f CMakeFiles/Makefile2 CMakeFiles/my_project.dir/all
  gmake[2]: Entering directory '/pathToCLionProject/my_project/cmake-build-default'
  /usr/bin/gmake -f CMakeFiles/my_project.dir/build.make CMakeFiles/my_project.dir/depend
  gmake[3]: Entering directory '/pathToCLionProject/my_project/cmake-build-default'
  cd /pathToCLionProject/my_project/cmake-build-default &amp;&amp; /pathToCLion/clion-2018.1.2/bin/cmake/bin/cmake -E cmake_depends "Unix Makefiles" /pathToCLionProject/my_project /pathToCLionProject/my_project /pathToCLionProject/my_project/cmake-build-default /pathToCLionProject/my_project/cmake-build-default /pathToCLionProject/my_project/cmake-build-default/CMakeFiles/my_project.dir/DependInfo.cmake --color=
  Scanning dependencies of target my_project
  gmake[3]: Leaving directory '/pathToCLionProject/my_project/cmake-build-default'
  /usr/bin/gmake -f CMakeFiles/my_project.dir/build.make CMakeFiles/my_project.dir/build
  gmake[3]: Entering directory '/pathToCLionProject/my_project/cmake-build-default'
  [ 50%] Building CXX object CMakeFiles/my_project.dir/dev/hmmenc_client/test.cpp.o
  /usr/bin/c++   -I/pathToCLionProject/my_project -I/pathToCLionProject/my_project/dev/hmmenc_client -I/usr/local/include/pqxx -I/usr/pgsql-10/include  -pthread -std=gnu++11 -o CMakeFiles/my_project.dir/dev/hmmenc_client/test.cpp.o -c /pathToCLionProject/my_project/dev/hmmenc_client/test.cpp
  /pathToCLionProject/my_project/dev/hmmenc_client/test.cpp: In function ‘int main()’:
  /pathToCLionProject/my_project/dev/hmmenc_client/test.cpp:9:10: error: ‘array’ is not a member of ‘std’
       std::array&lt;std::uint64_t, 3&gt; arr;
            ^~~~~
  /pathToCLionProject/my_project/dev/hmmenc_client/test.cpp:9:10: note: ‘std::array’ is defined in header ‘&lt;array&gt;’; did you forget to ‘#include &lt;array&gt;’?
  /pathToCLionProject/my_project/dev/hmmenc_client/test.cpp:6:1:
  +#include &lt;array&gt;
  
  /pathToCLionProject/my_project/dev/hmmenc_client/test.cpp:9:10:
       std::array&lt;std::uint64_t, 3&gt; arr;
            ^~~~~
  /pathToCLionProject/my_project/dev/hmmenc_client/test.cpp:9:29: error: expected primary-expression before ‘,’ token
       std::array&lt;std::uint64_t, 3&gt; arr;
                               ^
  /pathToCLionProject/my_project/dev/hmmenc_client/test.cpp:9:34: error: ‘arr’ was not declared in this scope
       std::array&lt;std::uint64_t, 3&gt; arr;
                                    ^~~
  gmake[3]: *** [CMakeFiles/my_project.dir/build.make:66: CMakeFiles/my_project.dir/dev/hmmenc_client/test.cpp.o] Error 1
  gmake[3]: Leaving directory '/pathToCLionProject/my_project/cmake-build-default'
  gmake[2]: *** [CMakeFiles/Makefile2:71: CMakeFiles/my_project.dir/all] Error 2
  gmake[2]: Leaving directory '/pathToCLionProject/my_project/cmake-build-default'
  gmake[1]: *** [CMakeFiles/Makefile2:83: CMakeFiles/my_project.dir/rule] Error 2
  gmake[1]: Leaving directory '/pathToCLionProject/my_project/cmake-build-default'
  gmake: *** [Makefile:121: my_project] Error 2
  </code></pre>
  
  <p>This is my g++ version: gcc version 8.1.1 20180502 (Red Hat 8.1.1-1) (GCC). What can cause this error?</p>