Re: new(nothrow not even from constructor)
In article <iercbt$t2j$1@speranza.aioe.org>,
Ruslan Mullakhmetov <tiabaldu@gmail.com> wrote:
On 12/22/2010 12:10 AM, red floyd wrote:
On Dec 20, 11:30 pm, Ruslan Mullakhmetov<tiaba...@gmail.com> wrote:
On 12/21/2010 5:22 AM, red floyd wrote:
On 12/20/2010 11:47 AM, Ruslan Mullakhmetov wrote:
you could probably use operator new overloading, but i'm not sure. never
overloaded one.
Or you could do this:
template<typename T>
T* new_thread(Func_type f, int state)
{
T* ret = NULL;
try {
ret = new Thread(f, state);
}
catch (...) {
// do something, or not
}
return ret;
}
Or I think it makes sense to get new_thread as static function-member of
Thread class say Thread::create. I'd prefer this, cause it number of
reduces global scoped free functions.
Yeah, I kind of switched gears mid-stream -- I started with a generic
template to deal with any type of create and then halfway through
switched to "Thread" specific -- mainly because I couldn't remember
the syntax for variadic templates.
My intent was to provide a generic "new" for OP that catches all
exceptions, including those thrown by the constructor.
I'm sorry, didn't take into account that it was templatized. I think,
there is no need for variadic templates to make it general new. SFINAE
allow, if i'm not mistaken to make variable number of parameters passed
to constructor through this generalized exception-free new.
template<typename T>
T* my_new()
{
T* ret = NULL;
try {
ret = new T;
}
catch (...) {
// do something, or not
}
return ret;
}
template<typename T, typename P1>
T* my_new(P1 p1)
{
T* ret = NULL;
try {
ret = new T(p1);
}
catch (...) {
// do something, or not
}
return ret;
}
template<typename T, typename P1, typename P2>
T* my_new(P1 p1, P2 p2)
{
T* ret = NULL;
try {
ret = new T(p1, p2);
}
catch (...) {
// do something, or not
}
return ret;
}
//...
I am sorry but this is awful. Yes, it will work. But all that just to
avoid using exceptions correctly and to produce what will be probably
exception unsafe code.
Really, the only correct solution is to give up on the old C liking of
malloc returning a NULL pointer on failure and accept exceptions.
The OP is lying to himself. He wants to be able to code as if
exceptions didn't exist. But they do and if he uses any of the
standard C++ library, they are there.
Typically, peoples that try to to ignore exception and act as if they
had never been introduced produce unsafe code that look like it might
handle error at first sight but in fact doesn't.