Could u tell me the version of your clang?

[4va1anch3]

when i do 'clang++ main.cpp -std=c++1z -Wno-gnu-string-literal-operator-template -D COMMAND -o tetris ; ./tetris' , there are many compile errors. And I do it in Ubuntu 14.04, clang 3.8.0. Is it the problem of my compiler or os?

[mattbierner]

Can you please post up the set of errors so that I have an idea of what may be going wrong.

The compiler version looks fine and there should not be anything too platform specific in the code.

[4va1anch3]

The set of errors and compiler information are in the attached *.txt.
compile error.txt

[mattbierner]

I can't repo the issue, but from the first error on in the file:

no member named 'gets' in the global namespace
using ::gets;

this report looks relevant (link to bug)

Also, try targeting -std=c++1y / -std=c++14 instead too, which may be more stable for that version of GCC. I don't recall using anything 1z specific, besides playing around with fold expressions.

Does an main.cpp file with just:

#include <iostream>
#include <fstream>

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

compile with the same command line arguments?

[4va1anch3]

I do it as you suggested. Now I know why it had compile errors. It seems clang searched for necessary header files and used header files under gcc. However, the version of gcc is too low in my pc. When I use g++ 5.3 as my compiler, there is no error. Thanks a lot for your help! BTW: do u know how to set the path of gcc for clang, because I prefer clang as my compiler but I do not find a way to do it.