By using Dev-C++, I used lambda expression, I want to know that if I white:

typedef std::vector<int> vect1;
std::vector<vect1> vect2;

vect2  vect2Instance;

then

std::for_each(vect2Instance.begin(),vect2Instance.end(),

         std::for_each(_1.begin(),_1.end(),_1+=2));

is legal or not? And if legal ,Does the first two _1's mean a number

 in vect2 (i.e. a vect1) and the last _1 is a number in vect1(i.e. a int)?

Can any one with kindness help me?