Proper idiom for std::string assignment

Question

When constructing a std::string from a const char*, I often use the following pattern:

const char* p = GetString();
std::string s(p);

I suppose I could use the similar pattern:

const char* p = GetString();
std::string s = p;

But, when I want to assign, rather than construct, to a std::string from a const char*, I have too many choices:

s = p;
s.assign(p);
std::string(p).swap(s);

Are the choices above more-or-less equivalent? Which should I prefer, and why?

Answer 1

Go for readability, and just use the idiomatic operator= for assignment. Also, directly construct the std::string from the const char*.

std::string s(GetString());
s = GetString();