楼主用的是支持c++11的编译器吧，

C++11新增了模板类array
{}初始化的方法，仅被最新的C++11标准支持，有个专门的术语：initializer-list

在不支持c++11的编译器上会报错， 比如在我的机器上报错如下：

   #include <array>
   #include <iostream>
   using namespace std;
   
   int main()
   {
       array<int, 3> a;
       a = {0, 1, 2}; 
       cout<<a[1]<<endl;
       return 0;
   }

In file included from /usr/include/c++/4.9/array:35:0,

from huakuohao.cpp:1:
/usr/include/c++/4.9/bits/c++0x_warning.h:32:2: error: #error This file requires     
compiler and library support for the ISO C++ 2011 standard. This support is currently experimental, and must be enabled with the -std=c++11 or -std=gnu++11 compiler options.
 #error This file requires compiler and library support for the \
  ^
huakuohao.cpp: In function ‘int main()’:
huakuohao.cpp:7:5: error: ‘array’ was not declared in this scope
huakuohao.cpp:8:17: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11