I think that the following `idiom' was often used:

    // necessary includes

    cout >> "Enter file name -> ";
    String file_name;
    ifstream (file_name); // or: ofstream (file_name);

(I used `S' (not `s') because this is not a proposed standard string
class.)

ifstream constructor expects const char*, but above call was possible
because String classes (eg. in libg++) used to have:
    String::operator const char*() const
(or something similar).

According to proposed standard, one should write:
    ifstream (file_name.c_str());
because implicit conversion of string to const char* is not defined.

I agree that implicit conversion is (almost always) dangerous, and I
_do not_ propose to add conversion operator to string class. Instead, I
think that fstream classes (beside, or even instead of, constructors that
take const char*s) should also have constructors that take strings.
In many C++ books one can read that plain C arrays (including char[]s and
char*s) are to low level, and that with classes (eg. vectors and strings)
one can work on higher levels of abstraction. fstreams are `better' than
cstdio functions, but, because of const char* parameters, they are still
to low level.


fresl

-----------
Kresimir Fresl
Faculty of Civil Engineering, Zagreb, Croatia
email: fresl@master.grad.hr
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