C++: is string.empty() always equivalent to string == “”?

Question

Can I make an assumption that given

std::string str;
... // do something to str

Is the following statement is always true?

Answer 1

Normally, yes.

But if someone decides to redefine an operator then all bets are off:

bool operator == (const std::string& a, const char b[])
{
    return a != b; // paging www.thedailywtf.com
}