Definition of struct template value in constructor / member function

Question

I'm working with a Pascal library that uses UCSD Strings. I created this template struct for making working with them easier:

template <std::size_t N>
struct DString {
    unsigned Reference, Size = N;
    char String[N];
};
#define MAKE_STRING(X) DString<sizeof(X)>{ 0x0FFFFFFFF, sizeof(X) - 1, X}

auto foo = MAKE_STRING("Foo");

I know it does not cover WideChar cases but the library does neither in the first place so I'm safe in that regard.

Anyway, my problem is that I don't want to use a macro and instead would like to create a constructor. So I was wondering if does C++ offers a possibility of implementing something like this pseudocode:

template <std::size_t N>
struct DString {
    unsigned Reference, Size = N;
    char String[N];
    DString<sizeof(s)>(const char* s, unsigned r = 0x0FFFFFFFF): 
        String(s), Reference(r) {}
};

auto foo = DString("Foo");

Of course, it does not need to be a "constructor". It is just an example.

I also tried this:

template <std::size_t N>
struct DString {
    unsigned Reference, Size = N;
    char String[N];

    inline static DString build(const char* X) {
        return DString<sizeof(X)>{ 0x0FFFFFFFF, sizeof(X) - 1, X};
    }
};

auto foo = DString::build("Foo");

But that in itself represents another issue. Because now I cannot reference the static function from DString without doing DString< size >::build(...);.

What can I do in this case?