[Boost-testing] A question on for_each() and placeholder.Can any one with kindness help me?

Subject: [Boost-testing] A question on for_each() and placeholder.Can any one with kindness help me?
From: fmingu (fmingu_at_[hidden])
Date: 2009-06-26 20:57:05

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?