Why C++ 'Standard' won't support function definition inside another function ?

I have search through google/stack overflow etc. but I could not find the proper/exact solution for this. I know latest C++ revision supports Lambda function by which we can achieve, and also I know we should avoid defining a function inside another function. But I'm curious why can not we have function definition inside function according to C++ standard?.

like following:

int print(){

 void test(){
          //statements
  }

}