In file included from /Users/czy/Desktop/dsdx.cpp:1:
In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/iostream:38:
In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/ios:216:
In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/__locale:15:
/Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/string:663:13: error: use of undeclared identifier '_LIBCPP_ASSERT'
_LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
^
/Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/string:723:13: error: use of undeclared identifier '_LIBCPP_ASSERT'
_LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
^
/Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/string:853:5: error: use of undeclared identifier '_LIBCPP_ASSERT'
_LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
^
/Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/string:974:5: error: use of undeclared identifier '_LIBCPP_ASSERT'
_LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
^
4 errors generated.
[Finished in 0.8s with exit code 1]
[shell_cmd: g++ "/Users/czy/Desktop/dsdx.cpp" -o "/Users/czy/Desktop/dsdx"]
[dir: /Users/czy/Desktop]
[path: /usr/bin:/bin:/usr/sbin:/sbin]
以上是具体的错误代码。求大神帮帮我该怎么办？现在完全就不能用了。

同求，我的黑苹果上也出现有无法调用的问题？请问楼主你的是白苹果吗？