@programminginc - страница 1452

Ritwik

But it prints wrong

Ritwik

Where is the mistake

Ritwik

??

Anonymous

Here, is the addresses of a and b the same? Or 'b' with a different address from 'a' contains the address of 'a' ?

Also, & performs different operations on the context that you use it, it can return the address or pass a reference. Which is a little confusing. Also it's a bitwise operation in another context.

Anonymous

Modulo is evil use divide

Anonymous

while(i<=500); getch(); Are you for real? wtf?

Ritwik

while(i<=500); getch(); Are you for real? wtf?

Why..??

Anonymous

What are you doing that for?

Anonymous

is that a do while?

Anonymous

why is there no do at the beginning?

Ritwik

is that a do while?

Yes

Anonymous

do { } while();

Anonymous

i've never seen some one use while at the end of a statement

Ritwik

do { } while();

Sorry I forget to write that..

Anonymous

while() { }

Anonymous

np i was just confused

Anonymous

looked like you where trying to loop getch() 500 times

Ritwik

np i was just confused

Can you found where is the problem

Anonymous

hows it not working? the result number

Ritwik

hows it not working? the result number

125 and 216

Anonymous

Honestly I have no idea why your armstrong algo is not working, i'm not going to compile it for you atm but I suggest making print() breakpoints to output each stage of the calculation until you find the step where it goes wrong

Francisco

We really prefer a code snippet right in Telegram or a link to the code via pastebin, compiler explorer, etc

Dima

Found a good article, yeah it’s kinda old but still https://www.gdcvault.com/play/1022186/Parallelizing-the-Naughty-Dog-Engine

Anonymous

The compiler you are using matters most but don't know where to get compiler to download.

Dima

what’s practical difference between SO_REUSEPORT and SO_LINGER?

Dima

like… docs almost identical, or I am missing something

Ибраги́м

The compiler you are using matters most but don't know where to get compiler to download.

?

Ибраги́м

what’s practical difference between SO_REUSEPORT and SO_LINGER?

SO_REUSEPORT (since Linux 3.9) Permits multiple AF_INET or AF_INET6 sockets to be bound to an identical socket address. This option must be set on each socket (including the first socket) prior to calling bind(2) on the socket. To prevent port hijacking, all of the pro‐ cesses binding to the same address must have the same effec‐ tive UID. This option can be employed with both TCP and UDP sockets. For TCP sockets, this option allows accept(2) load distribu‐ tion in a multi-threaded server to be improved by using a dis‐ tinct listener socket for each thread. This provides improved load distribution as compared to traditional techniques such using a single accept(2)ing thread that distributes connec‐ tions, or having multiple threads that compete to accept(2) from the same socket. For UDP sockets, the use of this option can provide better distribution of incoming datagrams to multiple processes (or threads) as compared to the traditional technique of having multiple processes compete to receive datagrams on the same socket.

Ибраги́м

SO_LINGER Sets or gets the SO_LINGER option. The argument is a linger structure. struct linger { int l_onoff; /* linger active */ int l_linger; /* how many seconds to linger for */ }; When enabled, a close(2) or shutdown(2) will not return until all queued messages for the socket have been successfully sent or the linger timeout has been reached. Otherwise, the call returns immediately and the closing is done in the background. When the socket is closed as part of exit(2), it always lingers in the background.

Ибраги́м

Not So the samey

Dima

Wait.. I must have been reading the same docs lol

Daniel

Hi guys! Wtf is this? https://github.com/RXDYE/oopLab6 I get undefined reference error when function is defined in cpp-file. When it's defined in header but OUT of the class linker see it.

Pavel

Yep, with template function/class you need to put implementation in the same translation unit (in your case in header), to let the compiler to generate the code; or to have implementation for specific types, in this case it's working like usual function/class.

🐰🐾 سمیه

Every object in C/C++ is a *typed* *memory snippet*. Here, int a declares a is an object with type int, while &a get its memory address; int* b declares b is an object with type int*, whose value represent the address of an int object, while &b get its memory address. If you want to store the address of b, you'll have to use int** c = &b;. b's value is the address of a.

When using &b, is the address of b created or it exists in object &b?

BinaryByter

>compiler knows address of every local variable are you drunk?

BinaryByter

local variable adresses aren't known at compile time

BinaryByter

neither are global variable adresses

BinaryByter

Umm

BinaryByter

this isn't a variable adress

BinaryByter

this is merely an offset

BinaryByter

Or rather: how do you know where in memory the program is loaded?

Daniel

wow. Thank you guys

BinaryByter

in this case, the global variable is an offset

BinaryByter

the linker will mark it as an offset at linkage

BinaryByter

and the kernel will fill in the gap when loading the executable

Anonymous

Hi

🐰🐾 سمیه

what's lvalue?

BinaryByter

its a variable

BinaryByter

try *(++y)

olli

what's lvalue?

n1570 - 6.3.2.1 An lvalue is an expression (with an object type other than void) that potentially designates an object; if an lvalue does not designate an object when it is evaluated, the behavior is undeﬁned. [...]

🐰🐾 سمیه

n1570 - 6.3.2.1 An lvalue is an expression (with an object type other than void) that potentially designates an object; if an lvalue does not designate an object when it is evaluated, the behavior is undeﬁned. [...]

incrementing a pointer by ++ operator, increments its value, which is an adress, by 1. In contrast, incrementing by number ( like y+1, and y is a pointer), makes it to point the next object ( char or int ... etc.). true?

🐰🐾 سمیه

error

🐰🐾 سمیه

here for ++y, I got below error. but by replacing it with *(y+1), it printed string b.

olli

incrementing a pointer by ++ operator, increments its value, which is an adress, by 1. In contrast, incrementing by number ( like y+1, and y is a pointer), makes it to point the next object ( char or int ... etc.). true?

y is an array or char pointer (hence cannot be incremented) 6.3.2.1 further states [...] A modiﬁable lvalue is an lvalue that does not have array type [...]

Pavel

here for ++y, I got below error. but by replacing it with *(y+1), it printed string b.

In addition, ++y and y+1 do different things, first is modifying value of y

🐰🐾 سمیه

In addition, ++y and y+1 do different things, first is modifying value of y

and second?

olli

and second?

does not change y and instead yields a temporary

olli

it's the same with int x = 3; ++x; // increments x (so x is 4) int y = x + 1; (does not change x but adds 1, so y is 5)

🐰🐾 سمیه

in case of pointers, y +1 points to the next object of its type. right?

olli

in case of pointers, y +1 points to the next object of its type. right?

yes

Anonymous

SO_REUSEPORT (since Linux 3.9) Permits multiple AF_INET or AF_INET6 sockets to be bound to an identical socket address. This option must be set on each socket (including the first socket) prior to calling bind(2) on the socket. To prevent port hijacking, all of the pro‐ cesses binding to the same address must have the same effec‐ tive UID. This option can be employed with both TCP and UDP sockets. For TCP sockets, this option allows accept(2) load distribu‐ tion in a multi-threaded server to be improved by using a dis‐ tinct listener socket for each thread. This provides improved load distribution as compared to traditional techniques such using a single accept(2)ing thread that distributes connec‐ tions, or having multiple threads that compete to accept(2) from the same socket. For UDP sockets, the use of this option can provide better distribution of incoming datagrams to multiple processes (or threads) as compared to the traditional technique of having multiple processes compete to receive datagrams on the same socket.

there was so_reuseport is the bomb for multi-threading

🐰🐾 سمیه

yes

So, why here at the above and below arrows, it walks through the elements by ++ operator?

🐰🐾 سمیه

or for example in copy fuction void copy( char *s, char *t ) for ( ; *s = *t; s++, t++);

🐰🐾 سمیه

or for example in copy fuction void copy( char *s, char *t ) for ( ; *s = *t; s++, t++);

here also ++ operator is used to go to next element.

🐰🐾 سمیه

I'm badly confused😟

Pavel

So, why here at the above and below arrows, it walks through the elements by ++ operator?

Well, this is a bit different You have a pointer to array of three elements of type char* In the example you've sent it's basically a char** (because the size is not given). In the memory it will be the same thing, but compiler knows more information in your case and can prohibit you of doing some unsafe things with the pointer. I'm not actually familiar with C-style arrays, so I may be wrong (hope I will be corrected by other uses then). But reading your code I assume that incrementing the pointer there makes no sense.

🐰🐾 سمیه

Well, this is a bit different You have a pointer to array of three elements of type char* In the example you've sent it's basically a char** (because the size is not given). In the memory it will be the same thing, but compiler knows more information in your case and can prohibit you of doing some unsafe things with the pointer. I'm not actually familiar with C-style arrays, so I may be wrong (hope I will be corrected by other uses then). But reading your code I assume that incrementing the pointer there makes no sense.