Proposed resolution:

This wording is relative to N4861.

1. Modify [ifstream], class template basic_ifstream synopsis, as indicated:

   […]
   explicit basic_ifstream(const string& s,
                           ios_base::openmode mode = ios_base::in);
   template<class T>
   explicit basic_ifstream(const filesystem::pathT& s,
                           ios_base::openmode mode = ios_base::in);
   […]
   

2. Modify [ifstream.cons] as indicated:

   explicit basic_ifstream(const string& s,
                           ios_base::openmode mode = ios_base::in);
   

   -?- Effects: Equivalent to: basic_ifstream(s.c_str(), mode).

   template<class T>
   explicit basic_ifstream(const filesystem::pathT& s,
                           ios_base::openmode mode = ios_base::in);
   

   -?- Constraints: is_same_v<T, filesystem::path> is true.

   -3- Effects: Equivalent to: basic_ifstream(s.c_str(), mode).

3. Modify [ofstream], class template basic_ofstream synopsis, as indicated:

   […]
   explicit basic_ofstream(const string& s,
                           ios_base::openmode mode = ios_base::out);
   template<class T>
   explicit basic_ofstream(const filesystem::pathT& s,
                           ios_base::openmode mode = ios_base::out);
   […]
   

4. Modify [ofstream.cons] as indicated:

   explicit basic_ofstream(const string& s,
                           ios_base::openmode mode = ios_base::out);
   

   -?- Effects: Equivalent to: basic_ofstream(s.c_str(), mode).

   template<class T>
   explicit basic_ofstream(const filesystem::pathT& s,
                           ios_base::openmode mode = ios_base::out);
   

   -?- Constraints: is_same_v<T, filesystem::path> is true.

   -3- Effects: Equivalent to: basic_ofstream(s.c_str(), mode).

5. Modify [fstream], class template basic_fstream synopsis, as indicated:

   […]
   explicit basic_fstream(
     const string& s,
     ios_base::openmode mode = ios_base::in | ios_base::out);
   template<class T>
   explicit basic_fstream(
     const filesystem::pathT& s,
     ios_base::openmode mode = ios_base::in | ios_base::out);
   […]
   

6. Modify [fstream.cons] as indicated:

   explicit basic_fstream(
     const string& s,
     ios_base::openmode mode = ios_base::in | ios_base::out);
   

   -?- Effects: Equivalent to: basic_fstream(s.c_str(), mode).

   template<class T>
   explicit basic_fstream(
     const filesystem::pathT& s,
     ios_base::openmode mode = ios_base::in | ios_base::out);
   

   -?- Constraints: is_same_v<T, filesystem::path> is true.

   -3- Effects: Equivalent to: basic_fstream(s.c_str(), mode).