C++11 deleted/defaulted constructors

I'm a bit confused about how/why the contructors are called in C++11 and C++17.

#include <iostream>
using namespace std;

//---

template<typename T>
struct StructTest
{
public:
  const T Var = -1;

  //---

  // constexpr StructTest() = delete;  // 1
  // constexpr StructTest() = default; // 2

  // constexpr StructTest(const StructTest &Source) = delete;                  // 3
  // constexpr StructTest(const StructTest &Source) = default;                 // 4
  // constexpr StructTest(const StructTest &Source) {cout << "Copy" << endl;}; // 5
};

//---

StructTest<int> A{};
StructTest<int> A1{1};
StructTest<int> A2(A);

//---

int main(void)
{
  return(0);
};

So I'm confused by what happens when I uncomment some combination of lines (and compiling with the c++17 standard flag with clang):

• 1, Compiles. List init's for A and A1, and the default copy constructor for A2
• 2, Compiles. Default constructor for A and list init A1?, and the default copy constructor for A2
• 1 + 3 or 2 + 3, Fails to compile because of the deleted copy constructor for A2
• 1 + 4, Compiles. Default constructor for A and list init A1?, and the default copy constructor for A2
• 2 + 4, Compiles. Default constructor for A and list init A1?, and the default copy constructor for A2
• 1 + 5, Fails to compile. Says A is missing(deleted) a default constructor, and no matching constructor for A1?
• 2 + 5, Fails to compile. No matching constructor for A1?

I think I understand most of this, but I'm confused why the 1 + 5, and 2 + 5 compiles fail. Could anyone explain the logic the compiler is using to select the constructors that it's going to use, and why it fails to compile?

If the constructors that I think are being called in the other cases are wrong, could you also point out what is being called, and why?

Andy.