Confusing Template error

Question

I\'ve been playing with clang a while, and I stumbled upon \"test/SemaTemplate/dependent-template-recover.cpp\" (in the clang distribution) which is supposed to provide hint

Answer 1

In addition to the points others made, notice that sometimes the compiler couldn't make up his mind and both interpretations can yield alternative valid programs when instantiating

#include 

template
struct A {
  typedef int R();

  template
  static U *f(int) { 
    return 0; 
  }

  static int f() { 
    return 0;
  }
};

template
bool g() {
  A a;
  return !(typename A::R*)a.f(0);
}


int main() {
  std::cout << g() << std::endl;
}

This prints 0 when omitting template before f but 1 when inserting it. I leave it as an exercise to figure out what the code does.