有一个非常简单的例子c++ project. foo.h：

class foo{  
    inline static const int array[3] = { 1, 2, 3 };  
};

foo.cc:

#include "foo.h"

foo a_foo;

main.cc:

#include "foo.h"
int main()
{
    foo b_foo;
}

使用g++通过以下命令编译时：

g++ -c *.cc
g++ *.o -o a.out

它只报告警告：

In file included from foo.cc:2:0:
foo.h:2:25: warning: inline variables are only available with -std=c++1z or -std=gnu++1z
 inline static const int array[3] = { 1, 2, 3 };
                         ^~~~~
In file included from main.cc:3:0:
foo.h:2:25: warning: inline variables are only available with -std=c++1z or -std=gnu++1z
 inline static const int array[3] = { 1, 2, 3 };
                         ^~~~~

但是当通过以下命令使用clang编译时：

clang -c *.cc
clang *.o -o a.out

甚至使用以下命令：

clang -std=c++1z -c *.cc
clang -std=c++1z *.o -o a.out

它报告错误：

In file included from foo.cc:2:
./foo.h:2:1: error: 'inline' can only appear on functions
inline static const int array[3] = { 1, 2, 3 };
^
./foo.h:2:25: error: in-class initializer for static data member of type 'const int [3]' requires 'constexpr' specifier
inline static const int array[3] = { 1, 2, 3 };
                        ^          ~~~~~~~~~~~
constexpr
2 errors generated.
In file included from main.cc:3:
./foo.h:2:1: error: 'inline' can only appear on functions
inline static const int array[3] = { 1, 2, 3 };
^
./foo.h:2:25: error: in-class initializer for static data member of type 'const int [3]' requires 'constexpr' specifier
inline static const int array[3] = { 1, 2, 3 };
                        ^          ~~~~~~~~~~~
constexpr
2 errors generated.

尝试了几次修改，但都失败了。如何纠正代码，使它也编译确定与clang？