Assign a nullptr to a std::string is safe?

Question

I was working on a little project and came to a situation where the following happened:

std::string myString;
#GetValue() returns a char*
myString = myObject         


        

Answer 1

It is runtime error.

You should do this:

myString = ValueOrEmpty(myObject.GetValue());

where ValueOrEmpty is defined as:

std::string ValueOrEmpty(const char* s)
{
    return s == nullptr ? std::string() : s;
}

Or you could return const char* (it makes better sense):

const char* ValueOrEmpty(const char* s)
{
    return s == nullptr ? "" : s; 
}

If you return const char*, then at the call-site, it will convert into std::string.