Does rule of not embedding std::string in exceptions still hold with move constructors?

Question

I heard some time ago that I should not create exception classes which would have fields of std::string type. That\'s what Boost website says. The rationale is that

Answer 1

Whether a copy of the string is made when an exception is thrown depends on the catch block.

Take this example:

#include 

struct A
{
};

void foo()
{
   throw A();
}

void test1()
{
   try
   {
      foo();
   }
   catch (A&& a)
   {
   }
}

void test2()
{
   try
   {
      foo();
   }
   catch (A const& a)
   {
   }
}

void test3()
{
   try
   {
      foo();
   }
   catch (A a)
   {
   }
}

int main()
{
   test1();
   test2();
   test3();
}

You will not make a copy of A in test1 or test2 but you will end up making a copy in test3.