用了点C++11特性，结果编译失败，编译参数加"-std=c++0x"，结果识别不出来。
$ g++ -v
Using built-in specs.
Target: amd64-undermydesk-freebsd
Configured with: FreeBSD/amd64 system compiler
Thread model: posix
gcc version 4.2.1 20070719 [FreeBSD]
C++0x/C++11 Support in GCC提到GCC 4.3版本之后才支持C++11特性，白折腾一把！ 好吧，我用gcc docker!