c++ - Difference between push_back and emplace_back in the case of a temporary value

Consider this snippet:

#include 

struct A
{
   A(int b): m_b(b) { }

private:
   int m_b;
};


int main()
{
    std::vector vec;

    vec.push_back( A(3) );

    vec.emplace_back( 3 );
}

In that particular case where a temporary value is passed, is there any difference between the 2 calls that a compiler won’t optimize away? Should I prefer one to the other?