C++11 object creation jungle [duplicate]

This code compiles

class X{};
int main() {
  X obj1;
  X obj2(obj1);
}

However, this does not compile

class X{};
int main() {
  X obj1(X());
  X obj2(obj1);
}

By default all constructors are created. When i use flower brackets it work, but i want to know whats wrong with this particular code. Why the compiler says the following

test.cpp: In function ‘int main()’:
test.cpp:4:13: error: no matching function for call to ‘X::X(X (&)(X (*)()))’
    4 |  X obj2(obj1);