What differences, if any, between C++03 and C++11 can be detected at run-time?

Question

It is possible to write a function, which, when compiled with a C compiler will return 0, and when compiled with a C++ compiler, will return 1 (the trivial sulution with

Answer 1

I got an inspiration from What breaking changes are introduced in C++11?:

#define u8 "abc"

bool isCpp0x() {
   const std::string s = u8"def"; // Previously "abcdef", now "def"
   return s == "def";
}

This is based on the new string literals that take precedence over macro expansion.