Generic lambdas Vs Standard template functions (What to use and When)

Generic Lambdas are a way of defining lambdas that read as follows:

auto identity = [](auto a){return a;}

Compare this with:

template <typename T>
T Identity(T t){return t;}

or with

template <typename T> 
struct Identity { T operator()(T a) { return a; } };

This is my understanding

1. 
   

   lambdas allow context capture using [&], [=], etc, I am not sure how this will be used / applied in generic lambdas. Is this the main difference ?

   
   


2. 
   

   generic lambdas can be cast to function pointers whereas, template specialisation can be cast to function pointers.

   
   

A simple real world example will be useful to understand what to use and when.

[Appended] Here is the generic lambda proposal : http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3559.pdf