请问这个枚举是啥意思

enum code
{
a   = 1 << 0,
b   = 1 << 1,
c   = 1 << 2,
d   = 1 << 3,
e   = 1 << 4,
f   = 1 << 5,
g   = 1 << 6,

MAX = 7
};

a = 1<<0
这个表达式是什么意思呢
[解决办法]
把 1 左移 0位的值赋值给a
[解决办法]
楼上正解，<<是左移位操作，结果就是

enum code
{
a   = 1,
b   = 2,
c   = 4,
d   = 8,
e   = 16,
f   = 32,
g   = 64,

MAX = 7
};