Search Results

Search found 20163 results on 807 pages for 'struct size'.

Page 121/807 | < Previous Page | 117 118 119 120 121 122 123 124 125 126 127 128  | Next Page >

  • Should this work?

    - by Noah Roberts
    I am trying to specialize a metafunction upon a type that has a function pointer as one of its parameters. The code compiles just fine but it will simply not match the type. #include <iostream> #include <boost/mpl/bool.hpp> #include <boost/mpl/identity.hpp> template < typename CONT, typename NAME, typename TYPE, TYPE (CONT::*getter)() const, void (CONT::*setter)(TYPE const&) > struct metafield_fun {}; struct test_field {}; struct test { int testing() const { return 5; } void testing(int const&) {} }; template < typename T > struct field_writable : boost::mpl::identity<T> {}; template < typename CONT, typename NAME, typename TYPE, TYPE (CONT::*getter)() const > struct field_writable< metafield_fun<CONT,NAME,TYPE,getter,0> > : boost::mpl::false_ {}; typedef metafield_fun<test, test_field, int, &test::testing, 0> unwritable; int main() { std::cout << typeid(field_writable<unwritable>::type).name() << std::endl; std::cin.get(); } Output is always the type passed in, never bool_.

    Read the article

  • How to decrease size of c++ source code? [closed]

    - by free0u
    For example #include <iostream> using namespace std; int main() { freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); int n; cin >> n; for (int i = 0; i < n; i++) { cout << i; } return 0; } Decrease: #include <fstream> int main() { std::ifstream y("input.txt"); std::ofstream z("output.txt"); int n, i = 0; y >> n; while(i < n) z << i++; exit(0); } What's about "fstream"? std::fstream y("input.txt"), z("output.txt") It's amazing but output is not correct.) "output.txt" isn't remaking. Output is writing from begin of file. How to decrease code? Just for fun)

    Read the article

  • Time taken for memcpy decreases after certain point

    - by tss
    I ve a code which increases the size of the memory(identified by a pointer) exponentially. Instead of realloc, I use malloc followed by memcpy.. Something like this.. int size=5,newsize; int *c = malloc(size*sizeof(int)); int *temp; while(1) { newsize=2*size; //begin time temp=malloc(newsize*sizeof(int)); memcpy(temp,c,size*sizeof(int)); //end time //print time in mili seconds c=temp; size=newsize; } Thus the number of bytes getting copied is increasing exponentially. The time required for this task also increases almost linearly with the increase in size. However after certain point, the time taken abruptly reduces to a very small value and then remains constant. I recorded time for similar code, copyin data(Of my own type) 5 -> 10 - 2 ms 10 -> 20 - 2 ms . . 2560 -> 5120 - 5 ms . . 20480 -> 40960 - 30 ms 40960 -> 91920 - 58 ms 367680 -> 735360 - 2 ms 735360 -> 1470720 - 2 ms 1470720 -> 2941440 - 2 ms What is the reason for this drop in time ? Does a more optimal memcpy method get called when the size is large ?

    Read the article

  • c# marshaling dynamic-length string

    - by mitsky
    i have a struct with dynamic length [StructLayout(LayoutKind.Sequential, Pack = 1)] struct PktAck { public Int32 code; [MarshalAs(UnmanagedType.LPStr)] public string text; } when i'm converting bytes[] to struct by: GCHandle handle = GCHandle.Alloc(value, GCHandleType.Pinned); stru = (T)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(T)); handle.Free(); i have a error, because size of struct less than size of bytes[] and "string text" is pointer to string... how can i use dynamic strings? or i can use only this: [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]

    Read the article

  • Is there a max size for POST parameter content?

    - by l3dx
    I'm troubleshooting a java app where XML is sent between two systems using HTTP POST and a servlet. I suspect that the problem is that the XML is growing way to big. Is it possible that this is the problem? Is there a limit? When it doesn't work, the request.getParameter("message") on the consumer side will return null. Both apps are running on tomcat

    Read the article

  • 'array bound is not an integer constant' when defining size of array in class, using an element of a const array

    - by user574733
    #ifndef QWERT_H #define QWERT_H const int x [] = {1, 2,}; const int z = 3; #endif #include <iostream> #include "qwert.h" class Class { int y [x[0]]; //error:array bound is not an integer constant int g [z]; //no problem }; int main () { int y [x[0]]; //no problem Class a_class; } I can't figure out why this doesn't work. Other people with this problem seem to be trying to dynamically allocate arrays. Any help is much appreciated.

    Read the article

  • How to determine IP used by client connecting to INADDR_ANY listener socket in C

    - by codebox_rob
    I have a network server application written in C, the listener is bound using INADDR_ANY so it can accept connections via any of the IP addresses of the host on which it is installed. I need to determine which of the server's IP addresses the client used when establishing its connection - actually I just need to know whether they connected via the loopback address 127.0.0.1 or not. Partial code sample as follows (I can post the whole thing if it helps): static struct sockaddr_in serverAddress; serverAddress.sin_family = AF_INET; serverAddress.sin_addr.s_addr = INADDR_ANY; serverAddress.sin_port = htons(port); bind(listener, (struct sockaddr *) &serverAddress, sizeof(serverAddress)); listen(listener, CONNECTION_BACKLOG); SOCKET socketfd; static struct sockaddr_in clientAddress; ... socketfd = accept(listener, (struct sockaddr *) &clientAddress, &length);

    Read the article

  • How to enforce DB field size limit to related Java String?

    - by Sri Sankaran
    What is the correct way to defend against trying to store more text than can be accommodated in a VARCHAR2 database field? Say the PARTNER_ROLE field of the REGISTRATIONS table is declared as VARCHAR2(80). This field is mapped in the Registration class in Java as public class Registration { @Column(name=”PARTNER_ROLE” length=”80”) private String partnerRole; } However, the setPartnerRole() method allows the user to stuff a string of any length. The problem is encountered only when one subsequently tries to insert or update the REGISTRATIONS record. Oracle complains. What is the correct way to handle this situation?

    Read the article

  • unused memory using 32 bit integer in C

    - by endmade
    I have the folowing struct of integers (32 bit environment): struct rgb { int r; int g; int b; }; Am I correct in saying that, since rgb component values (0-255) only require 8-bits(1 byte) to be represented, I am only using 1 byte of memory and leaving 3 bytes unused for each component? Also, if I instead did the following: struct rgb{ unsigned int r:8; unsigned int g:8; unsigned int b:8; }; Assuming that what I said above is correct, would using this new struct reduce the number of unused bytes to 1?

    Read the article

  • C++ Bubble Sorting for Singly Linked List [closed]

    - by user1119900
    I have implemented a simple word frequency program in C++. Everything but the sorting is OK, but the sorting in the following script does not work. Any emergent help will be great.. #include <stdio.h> #include <string.h> #include <stdlib.h> #include <ctype.h> #include <iostream> #include <fstream> #include <cstdio> using namespace std; #include "ProcessLines.h" struct WordCounter { char *word; int word_count; struct WordCounter *pNext; // pointer to the next word counter in the list }; /* pointer to first word counter in the list */ struct WordCounter *pStart = NULL; /* pointer to a word counter */ struct WordCounter *pCounter = NULL; /* Print statistics and words */ void PrintWords() { ... pCounter = pStart; bubbleSort(pCounter); ... } //end-PrintWords void bubbleSort(struct WordCounter *ptr) { WordCounter *temp = ptr; WordCounter *curr; for (bool didSwap = true; didSwap;) { didSwap = false; for (curr = ptr; curr->pNext != NULL; curr = curr->pNext) { if (curr->word > curr->pNext->word) { temp->word = curr->word; curr->word = curr->pNext->word; curr->pNext->word = temp->word; didSwap = true; } } } }

    Read the article

  • Shuffle array variables in a pre-specified order, without using extra memory of "size of input array"

    - by Eternal Learner
    Input : A[4] = {0,4,-1,1000} - Actual Array P[4] = {1,0,3,2} - Order to be reshuffled Output: A[4] = {4,0,1000,-1} Condition : Don't use an additional array as memory. Can use an extra variable or two. Problem : I have the below program in C++, but this fails for certain inputs of array P. #include<iostream> using namespace std; void swap(int *a_r,int *r) { int temp = *r; *r = *a_r; *a_r = temp; } int main() { int A[4] = {0,4,-1,1000}; int P[4] = {3,0,1,2}; int value = A[0] , dest = P[0]; for(int i=0; i<4;i++) { swap(&A[dest],&value); dest = P[dest]; } for(int i=0;i<4;i++) cout<<A[i]<<" "; }

    Read the article

  • C++ dynamic type construction and detection

    - by KneLL
    There was an interesting problem in C++, but it concerns more likely architecture. There are many (10, 20, 40, etc) classes that describe some characteristics (mix-in classes), for exmaple: struct Base { virtual ~Base() {} }; struct A : virtual public Base { int size; }; struct B : virtual public Base { float x, y; }; struct C : virtual public Base { bool some_bool_state; }; struct D : virtual public Base { string str; } // .... Primary module declares and exports a function (for simplicity just function declarations without classes): // .h file void operate(Base *pBase); // .cpp file void operate(Base *pBase) { // .... } Any other module can has a code like this: #include "mixins.h" #include "primary.h" class obj1_t : public A, public C, public D {}; class obj2_t : public B, public D {}; // ... void Pass() { obj1_t obj1; obj2_t obj2; operate(&obj1); operate(&obj2); } The question is how to know what the real type of given object in operate() without dynamic_cast and any type information in classes (constants, etc)? Function operate() is used with big array of objects in small time periods and dynamic_cast is too slow for it. And I don't want to include constants (enum obj_type { ... }) because this is not OOP-way. // module operate.cpp void some_operate(Base *pBase) { processA(pBase); processB(pBase); } void processA(A *pA) { } void processB(B *pB) { } I cannot directly pass a pBase to these functions. And it's impossible to have all possible combinations of classes, because I can add new classes just by including new .h files. As one of solutions that comed to mind, in editor application I can use a composite container: struct CompositeObject { vector<Base *pBase> parts; }; But editor does not need a time optimization and can use dynamic_cast for parts to determine the exact type. In operate() I cannot use this solution. So, is it possible to not use a dynamic_cast and type information to solve this problem? Or maybe I should use another architecture?

    Read the article

  • How do I split ONE array to two separate arrays based on magnitude size and a threshold?

    - by youhaveaBigego
    I have an array which has BIG numbers and small numbers in it. I got it from after running a log from WireShark. It is the total number of Bytes of TCP traffic. But Wireshark does not discriminate(it would actually try, and hence it will tell you the traffic stats of ALL types of traffic, but since This is how the Array look like : @Array=qw(10912980 10924534 10913356 10910304 10920426 10900658 10911266 10912088 10928972 10914718 10920770 10897774 10934258 10882186 10874126 8531 8217 3876 8147 8019 68157 3432 3350 3338 3280 3280 7845 7869 3072 3002 2828 8397 1328 1280 1240 1194 1193 1192 1194 6440 1148 1218 4236 1161 1100 1102 1148 1172 6305 1010 5437 3534 4623 4669 3617 4234 959 1121 1121 1075 3122 3076 1020 3030 628 2938 2938 1611 1611 1541 1541 1541 1541 1541 1541 1541 1541 1541 1541 1541 1541 583 370 178) When you look at these this array carefully, one thing is obvious to the human eye. There are really BIG numbers and small numbers. (Basically what I am saying is, there is the 1% class and low income class, no middle class). I want to split the array to two different arrays. That would require me to set a threshold. Array 1 should be ONLY the BIG numbers (10924534-10874126), and array 2 should be the smaller numbers (68157-178). Btw, the array is not sorted. User will NOT input the threshold, and hence should be determined smartly.

    Read the article

  • How to change the font size in table cells according to cells content ?

    - by misha-moroshko
    I have an HTML table which has incrementing numbers starting from 0 in its cells (left to right, up to bottom). I fixed in CSS the width and the height of the cells (40px width, 25px height, in my case). When the table becomes larger, the numbers inside it becomes large also (for example, the last number is 1266356). This causes the cells to be wider than I defined in the CSS, which expands the whole table accordingly. Instead, I would like the font of the numbers to be smaller to keep the width of the cell 40px. How can I accomplish this using CSS / Javascript / jQuery ?

    Read the article

< Previous Page | 117 118 119 120 121 122 123 124 125 126 127 128  | Next Page >