Intermediate results using expression templates

Question

in C++ Template Metaprogramming : Concepts, Tools, and Techniques from Boost and Beyond

... One drawback of expression templates is that they tend to

Answer 1

I don't understand your question. auto is going to be reused in C++0x for automatic type inference.

I personally see this as a drawback for expression templates since they often relay on having a smaller life span than the objects they are built upon which can turn out to be false if the expression template is captured as I explain here.

Answer 2

For now, you can always use BOOST_AUTO() in the place of C++0x's auto keyword to get intermediate results more easily.

Matrix x, y;
BOOST_AUTO(result, (x + y) * (x + y)); // or whatever.