how std::thread constructor detects rvalue reference?

Question

Obviously it is possible to pass an rvalue reference to std::thread constructor. My problem is with definition of this constructor in cppreference. It says that

Answer 1

auto s = std::decay_copy(std::string("hello"));

Is equivalent to:

template<>
std::string std::decay_copy(std::string&& src) {
    return std::string(std::move(src));
}

std::string s = decay_copy(std::string("hello"));