Pre-C++14 template metaprogramming and conditional operator

Question

From cppreference.com :

Such conditional operator was commonly used in C++11 constexpr programming prior to C++14.

 std::string str = 2+2==4 ? "ok" : throw std::logic_error("2+2 != 4"); 

What does cppreference refer to? What was the pre-C++14 idiom and why in C++14 that technique is no longer relevant?

Answer 1

In c++11 you could not have more than one statement, basically, in a constexpr function. In c++14 you can.

constexpr bool str(int x){
  return  2+2==x ? true : throw std::logic_error("2+2 != x");
}

vs c++14 :

constexpr bool str(int x){
  if (2+2==x)
    return true;
  else
     throw std::logic_error("2+2 != x");
}