My question was more of if you have multiple statements, instead of a single expression, you wanted to stick inside a macro and preserve the ability to call it within another expression.

For example:

  #define SOMEMACRO(x) do { \
     int y=0;               \
     for(int i=0; i<x; i++) \
       y=dosomething(y, i); \
  } while (0)

Which, of course, works fine if you call it as a statement. But it doesn't work if you want to somehow "return" the value of "y" from that: there's no way to embed that kind of loop into an expression.

He showed an example of using Apple's Blocks to solve that, can you do the same with C++0x lambdas?