hi there
i m trying to convert (viod *) data to (unsigned char) using
reinterpret_cas t as following
void *aData; // some data already provided
unsigned char c = reinterpret_cas t<unsingned char>(aData);
and the gcc is giving me the following error
-------------------------------------------------
reinterpret_cas t from
`void*' to `unsigned char' loses precision
-------------------------------------------------
is this what i m doing is valid Standard C++ ???
I have kept settings to treat all warning as Errors, so this is giving me
error
any suggestions ?? 6 2791
On Tue, 13 Jul 2004 12:59:59 +0530, hack_tick <ha*******@yaho o.com> wrote: hi there i m trying to convert (viod *) data to (unsigned char) using reinterpret_cas t as following
void *aData; // some data already provided
unsigned char c = reinterpret_cas t<unsingned char>(aData);
and the gcc is giving me the following error
------------------------------------------------- reinterpret_cas t from `void*' to `unsigned char' loses precision -------------------------------------------------
is this what i m doing is valid Standard C++ ???
I have kept settings to treat all warning as Errors, so this is giving me error
any suggestions ??
Converting void* to unsigned char is a completely meaningless thing to do.
As the warning states, void* is four bytes (probably) and unsigned char is
one byte, so you are losing information.
Are you sure you didn't mean to convert to unsigned char*? That would make
a lot more sense.
john
"hack_tick" <ha*******@yaho o.com> wrote in message
news:2l******** ****@uni-berlin.de... hi there i m trying to convert (viod *) data to (unsigned char) using reinterpret_cas t as following
void *aData; // some data already provided
unsigned char c = reinterpret_cas t<unsingned char>(aData);
and the gcc is giving me the following error
reinterpret_cas t means like telling the compiler that I know better than you
here, just carry out what I am saying. That's unsafe and compiler warns you
here that
it could be that the destination type is not big enough to hold the source
value. reinterpret_cas t is very much standard C++.
hi there
"John Harrison" <jo************ *@hotmail.com> wrote in message
news:opsa2ey3vg 212331@andronic us...
[..] Converting void* to unsigned char is a completely meaningless thing to do. As the warning states, void* is four bytes (probably) and unsigned char is one byte, so you are losing information.
Are you sure you didn't mean to convert to unsigned char*? That would make a lot more sense.
opps !! actually my mistake, it was (unsigned char *), sorry and thankx for
making me realize that
:-)
hack_tick wrote: hi there "John Harrison" <jo************ *@hotmail.com> wrote in message news:opsa2ey3vg 212331@andronic us... [..]
Converting void* to unsigned char is a completely meaningless thing to do. As the warning states, void* is four bytes (probably) and unsigned char is one byte, so you are losing information.
Are you sure you didn't mean to convert to unsigned char*? That would make a lot more sense.
opps !! actually my mistake, it was (unsigned char *), sorry and thankx for making me realize that :-)
I believe that you can use static_cast<> to cast a void* into
any-other-type*
hi there
"red floyd" <no*****@here.d ude> wrote in message
news:ip******** *********@newss vr25.news.prodi gy.com...
[..] I believe that you can use static_cast<> to cast a void* into any-other-type*
yup we can, i was doing all in hurry and forgt the actual data it was
containing(addr ess)
thanks for your reply :-)
hack_tick wrote: hi there "red floyd" <no*****@here.d ude> wrote in message news:ip******** *********@newss vr25.news.prodi gy.com... [..]
I believe that you can use static_cast<> to cast a void* into any-other-type*
yup we can, i was doing all in hurry and forgt the actual data it was containing(addr ess)
thanks for your reply :-)
just to add , reinterpret cast is best when you try to convert an
integer to a pointer. ( assuming the integer contains a valid address).
It is no doubt dangerous, ( and not portable, to add ) , but assuming
you know what you are doing , then it is best used in scenarios to
convert an integer to a pointer.
HTH
- Karthik. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
by: Suzanne Vogel |
last post by:
I'd like to convert a double to a binary representation. I can use the
"&" bit operation with a bit mask to convert *non* float types to binary
representations, but I can't use "&" on doubles.
To get around this limitation on double, I'd like to keep the bits of
the double the *same* but change its interpretation to long. I can use
"&" on longs. I tried to use reinterpret_cast for this purpose, but it
returned zero every time.
double...
|
by: Taran |
last post by:
Hi All,
I was trying some code which essentially does what the function 'func'
here does. To simplify the things and make a consise post I have
created a dummy app to show my problem.
The issue was to assign a value to an array of pointers. The selection
of array depends upon a condition and the void* ptr has to be casted to
the correct type and inserted in the array.
|
by: Peter |
last post by:
I never used reinterpret_cast -- probably because I don't know what it
means.
Can somebody enlighten me?
I looked into Stroustrup's "The annoted C++ reference manual" -- but
this was no help.
Can I assume that reinterpret_cast is not safe and should not be used?
Does it always succeed even if the cast is garbage?
|
by: tkirankumar |
last post by:
Hi all,
This is regarding the issue I am facing while porting the my
application from SuSe Linux to
Sun Solaris.
The Existing system details:
Itanium boxes 1mhz 4 processor 8 gb machines with SuSe Linux
$ uname -a
Linux longrtedged01 2.4.21-215-itanium2-smp #1 SMP Mon Apr 26 16:28:29
|
by: Noah Roberts |
last post by:
What steps do people take to make sure that when dealing with C API
callback functions that you do the appropriate reinterpret_cast<>? For
instance, today I ran into a situation in which the wrong type was the
target of a cast. Of course with a reinterpret_cast nothing complains
until the UB bites you in the ass. It seems to me that there ought to
be a way to deal with these kinds of functions yet still retain some
semblance of type...
| |
by: Lionel B |
last post by:
Greetings,
I have some code that is to read unformatted data from disc and interpret
it as blocks of unsigned integers. In an attempt to achieve efficiency
(it is pretty essential for my application that the code be
speed optimized ) I use reinterpret_cast to alias a block of chars read
in from disc as a block of integer "words". My existing code (see
simplified code below) appears to work well enough on the platforms
available to me,...
|
by: jasm |
last post by:
hello everybody!
I have used reinterpret_cast for interpret a class object as a char*.
This is the object:
template<class T>
class Coordinates {
public:
T *x;
T *y;
|
by: ciccio |
last post by:
Hi,
I was wondering what the main reason is why reinterpret_cast fails to work
as expected when using optimizations. Here is the simple example code which
fail to give the correct result when optimizing.
#include <iostream>
int main() {
long D1 = 0xbcfbc4f0d9b65179;
long D2 = 0xbcfbc4f0d9b65042;
|
by: Husyn Raj |
last post by:
class person
{ protected:
char name;
int age;
public:
void getdata()
{cout<<"Enter name";
cin>>name;
cout<<"Enter age";
cin>>age;
|
by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it.
First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
|
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
| |
by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
|
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
|
by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own....
Now, this would greatly impact the work of software developers. The idea...
|
by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
|
by: adsilva |
last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
|
by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
| |
by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
| |