syntax tl::expected for constructor member initializer list ?

[ArchNemSyS]

Trying to use TL::Expected in a Qt project as Qt doesn't play well with exceptions and is quasi C++ version locked to 17.

I am probably missing something really obvious, but I expected the code below to compile.

#include <include/tl/expected.hpp>

class Parent
{
private:
    int n =42;
};


class Child
{
public:
    Child() = delete;

private:
    Parent* myParent;

    explicit Child(Parent *p = nullptr)
    : myParent { p }
    {};
};



int main()
{
    // works
    tl::expected<int, std::string> AnswerToUniverse{42};
    
    
    Parent parent;
    Parent* ptr{ &parent };
    tl::expected<Child, std::string> child{parent};
    
    return 0;
}

Instead I get

/TLExpected/main.cpp:33: error: no matching function for call to ‘tl::expected<Child, std::__cxx11::basic_string<char> >::expected(<brace-enclosed initializer list>)’

/TLExpected/build/Desktop-Debug/_deps/tl-expected-src/include/tl/expected.hpp:233:
 error: no type named ‘type’ in ‘struct std::enable_if<false, void>’

Probably not relevant but I am pulling in tl::expected using CPM in the project cmakefile
VERSION 1.1.0
GIT_REPOSITORY "https://github.com/TartanLlama/expected"

[ArchNemSyS]

This works as per stack-overflow question, not only do I not understand it but it feels unnecessary for a movable type

#include <string>
#include <include/tl/expected.hpp>

class Parent
{
private:
    int n =42;
};


class Child
{
public:
    Child() = delete;

    static auto create(Parent *p) noexcept -> tl::expected<Child, std::string> {
        return tl::expected<Parent *, std::string>{p}.transform(
            [](Parent *p) { return Child{p}; });
    }

private:
    Parent* myParent;

    explicit Child(Parent *p = nullptr)
    : myParent { p }
    {};


};



int main()
{
    //works
    tl::expected<int, std::string> AnswerToUniverse{42};

    Parent parent;
    Parent* ptr{ &parent };

    //tl::expected<Child, std::string> child{ptr};

    tl::expected<Child, std::string> child = Child::create(ptr);
    return 0;
}