Re: Access Violation Problem
"Paavo Helde" <myfirstname@osa.pri.ee>
basic_string? Forget it.
CString is your friend in that case -- it has interface suitable for
about all tasks you have in the envirionment, and has implicit
conversion toward const char *, so you can start replacing the c-style
stuff without uglifying the user code.
This is about the worst advice one could give, exactly because of the
implicit conversion to const char*. This means that if some function f()
outputs a string, the following code compiles without any warning or
error:
const char* s = f();
And we arrived to gremlin-land. Yeah, that means that. So then what?
In C++ we have too many opportunities for dongling objects and references.
So any actually working system deals with that on reviews. Generally you're
not supposed to use raw pointers. And if any pointer or ref is stored, there
must be a proof for correct lifetime issues. Conversions, implicit or
explicit, adds quite nothing to that case.
Now imagine that f() returned a char* pointer originally (e.g. to a
static buffer, or to a string literal), and was later upgraded to return
a CString. I think this is exactly what OP wants to do.
You can hardly sell that conversion as sensible on a review.
If a static lifetime char* was returned, then you must return CString with a
similar lifetime, so the client code will just work fine. If you change
lifetime issues, like returning a temporary in stead of a stable thing, you
must revisit all usege places and adjust them. Capturing the temporary
correctly.
I am sure you and me could foresee the dangers and avoid the problems,
but I am not so sure at all about OP.
Whoever can't design the flow of data in a system is doomed to failure
regardless of tools used. Didn't the 'new age' languages like java,
promising Canaan with garbage collection enough proof? Making all the same
problems actually escalated?
(As a bonus you also dodge a ton of problems if decide to put some
code into DLL).
std::basic_string works as fine in dll-s as do std::vector and std::map,
not sure what problems you have in mind.
WOW, did you read MSDN recently or ever? Or tried to use them? You get
violent warning right ahead about the templates not being exported by
nature. Then will have an uphill battle. I didn't even mention what you get
for mixing ITERATOR_DEBUG_LEVEL, where you may get a linker warning at
least, but may just silently have ODR violation and the wildest crashes
imaginable...