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  • How to implement a simple queue properly?

    - by Stephen Hsu
    The current Go library doesn't provide the queue container. To implement a simple queue, I use circle array as the underlying data structure. It follows algorithms mentioned in TAOCP: Insert Y into queue X: X[R]<-Y; R<-(R+1)%M; if R=F then OVERFLOW. Delete Y from queue X: if F=R then UNDERFLOW; Y<-X[F]; F<-(F+1) % M. F: Front, R: Rear, M: Array length. Following is the code: package main import ( "fmt" ) type Queue struct { len int head, tail int q []int } func New(n int) *Queue { return &Queue{n, 0, 0, make([]int, n)} } func (p *Queue) Enqueue(x int) bool { p.q[p.tail] = x p.tail = (p.tail + 1) % p.len return p.head != p.tail } func (p *Queue) Dequeue() (int, bool) { if p.head == p.tail { return 0, false } x := p.q[p.head] p.head = (p.head + 1) % p.len return x, true } func main() { q := New(10) for i := 1; i < 13; i++ { fmt.Println(i, q.Enqueue(i)) } fmt.Println() for i := 1; i < 13; i++ { fmt.Println(q.Dequeue()) } } But the output is obviously wrong: 1 true 2 true 3 true 4 true 5 true 6 true 7 true 8 true 9 true 10 false 11 true 12 true 11 true 12 true 0 false 0 false 0 false 0 false 0 false 0 false 0 false 0 false 0 false 0 false I think I need one more field to make the code work properly. What do you suggest?

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  • Can I prevent a Linux user space pthread yielding in critical code?

    - by KermitG
    I am working on an user space app for an embedded Linux project using the 2.6.24.3 kernel. My app passes data between two file nodes by creating 2 pthreads that each sleep until a asynchronous IO operation completes at which point it wakes and runs a completion handler. The completion handlers need to keep track of how many transfers are pending and maintain a handful of linked lists that one thread will add to and the other will remove. // sleep here until events arrive or time out expires for(;;) { no_of_events = io_getevents(ctx, 1, num_events, events, &timeout); // Process each aio event that has completed or thrown an error for (i=0; i<no_of_events; i++) { // Get pointer to completion handler io_complete = (io_callback_t) events[i].data; // Get pointer to data object iocb = (struct iocb *) events[i].obj; // Call completion handler and pass it the data object io_complete(ctx, iocb, events[i].res, events[i].res2); } } My question is this... Is there a simple way I can prevent the currently active thread from yielding whilst it runs the completion handler rather than going down the mutex/spin lock route? Or failing that can Linux be configured to prevent yielding a pthread when a mutex/spin lock is held?

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  • Cassandra Batch_insert example in C#.net

    - by Sandeep
    Can any one please give me an example on how to work on Cassandra batch_insert in C# thrift client? If possible please let me know where am I going wrong in the following code. Dictionary dictionary = new Dictionary(); Dictionary subColumns = new Dictionary(); List listOfMutations = new List(); listOfMutations.Add(new Mutation() { Column_or_supercolumn = new ColumnOrSuperColumn() { Column = new Column() { Name = utf8Encoding.GetBytes("AA"), Value = utf8Encoding.GetBytes("Answer Automation"), Timestamp = timeStamp } } }); listOfMutations.Add(new Mutation() { Column_or_supercolumn = new ColumnOrSuperColumn() { Column = new Column() { Name = utf8Encoding.GetBytes("CT"), Value = utf8Encoding.GetBytes("Call Tracker"), Timestamp = timeStamp } } }); listOfMutations.Add( new Mutation() { Column_or_supercolumn = new ColumnOrSuperColumn() { Column = new Column() { Name = utf8Encoding.GetBytes("TL"), Value = utf8Encoding.GetBytes("Track That Lead"), Timestamp = timeStamp } } }); SuperColumn superColumn = new SuperColumn() { Name=utf8Encoding.GetBytes("Indatus") }; subColumns.Add("Super1", listOfMutations); dictionary.Add("Indatus", subColumns); client.batch_mutate("Keyspace1",dictionary, ConsistencyLevel.ONE); I understand that SuperColumn struct expects List but I does not have a list of Columns. Rather I have List. Thanks in Advance.

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  • Modifying C# dictionary value

    - by minjang
    I'm a C++ expert, but not at all for C#. I created a Dictionary<string, STATS>, where STATS is a simple struct. Once I built the dictionary with initial string and STATS pairs, I want to modify the dictionary's STATS value. In C++, it's very clear: Dictionary<string, STATS*> benchmarks; Initialize it... STATS* stats = benchmarks[item.Key]; // Touch stats directly However, I tried like this in C#: Dictionary<string, STATS> benchmarks = new Dictionary<string, STATS>(); // Initialize benchmarks with a bunch of STATS foreach (var item in _data) benchmarks.Add(item.app_name, item); foreach (KeyValuePair<string, STATS> item in benchmarks) { // I want to modify STATS value inside of benchmarks dictionary. STATS stat_item = benchmarks[item.Key]; ParseOutputFile("foo", ref stat_item); // But, not modified in benchmarks... stat_item is just a copy. } This is a really novice problem, but wasn't easy to find an answer. EDIT: I also tried like the following: STATS stat_item = benchmarks[item.Key]; ParseOutputFile(file_name, ref stat_item); benchmarks[item.Key] = stat_item; However, I got the exception since such action invalidates Dictionary: Unhandled Exception: System.InvalidOperationException: Collection was modified; enumeration operation may not execute. at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource) at System.Collections.Generic.Dictionary`2.Enumerator.MoveNext() at helper.Program.Main(String[] args) in D:\dev\\helper\Program.cs:line 75

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  • How to use dirent.h correctly.

    - by Nick
    Hello, I am new to C++ and I am experimenting with the dirent.h header to manipulate directory entries. The following little app compiles but pukes after you supple a directory name. Can someone give me a hint? The int quit is there to provide a while loop. I removed the loop in an attempt to isolate my problem. thanks! #include <iostream> #include <dirent.h> using namespace std; int main() { char *dirname = 0; DIR *pd = 0; struct dirent *pdirent = 0; int quit = 1; cout<< "Enter a directory path to open (leave blank to quit):\n"; cin >> dirname; if(dirname == NULL) { quit = 0; } pd = opendir(dirname); if(pd == NULL) { cout << "ERROR: Please provide a valid directory path.\n"; } return 0; }

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  • Indices instead of pointers in STL containers?

    - by zvrba
    Due to specific requirements [*], I need a singly-linked list implementation that uses integer indices instead of pointers to link nodes. The indices are always interpreted with respect to a vector containing the list nodes. I thought I might achieve this by defining my own allocator, but looking into the gcc's implementation of , they explicitly use pointers for the link fields in the list nodes (i.e., they do not use the pointer type provided by the allocator): struct _List_node_base { _List_node_base* _M_next; ///< Self-explanatory _List_node_base* _M_prev; ///< Self-explanatory ... } (For this purpose, the allocator interface is also deficient in that it does not define a dereference function; "dereferencing" an integer index always needs a pointer to the underlying storage.) Do you know a library of STL-like data structures (i am mostly in need of singly- and doubly-linked list) that use indices (wrt. a base vector) instead of pointers to link nodes? [*] Saving space: the lists will contain many 32-bit integers. With two pointers per node (STL list is doubly-linked), the overhead is 200%, or 400% on 64-bit platform, not counting the overhead of the default allocator.

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  • What is the merit of the "function" type (not "pointer to function")

    - by anatolyg
    Reading the C++ Standard, i see that there are "function" types and "pointer to function" types: typedef int func(int); // function typedef int (*pfunc)(int); // pointer to function typedef func* pfunc; // same as above I have never seen the function types used outside of examples (or maybe i didn't recognize their usage?). Some examples: func increase, decrease; // declares two functions int increase(int), decrease(int); // same as above int increase(int x) {return x + 1;} // cannot use the typedef when defining functions int decrease(int x) {return x - 1;} // cannot use the typedef when defining functions struct mystruct { func add, subtract, multiply; // declares three member functions int member; }; int mystruct::add(int x) {return x + member;} // cannot use the typedef int mystruct::subtract(int x) {return x - member;} int main() { func k; // the syntax is correct but the variable k is useless! mystruct myobject; myobject.member = 4; cout << increase(5) << ' ' << decrease(5) << '\n'; // outputs 6 and 4 cout << myobject.add(5) << ' ' << myobject.subtract(5) << '\n'; // 9 and 1 } Seeing that the function types support syntax that doesn't appear in C (declaring member functions), i guess they are not just a part of C baggage that C++ has to support for backward compatibility. So is there any use for function types, other than demonstrating some funky syntax?

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  • mmap only needed pages of kernel buffer to user space

    - by axeoth
    See also this answer: http://stackoverflow.com/a/10770582/1284631 I need something similar, but without having to allocate a buffer: the buffer is large, in theory, but the user space program only needs to access some parts of it (it mocks some registers of a hardware). As I cannot allocate with vmalloc_user() such a large buffer (kernel 32 bit, in embedded environment, no swap...), I followed the same approach as in the quoted answer, trying to allocate only those pages that are really requested by the user space. So: I use a my_mmap() function for the device file (actually, is the .mmap field of a struct uio_info) to set up the fields of the vma, then, in the vm_area_struct's .fault field (also named my_fault()), I should return a page. except that: In the my_fault() method of vm_area_struct, I cannot obtain a page through: vmf->page=vmalloc_to_page(my_buf + (vmf->pgoff << PAGE_SHIFT)); since there is no allocated buffer: my_buf = vmalloc_user(MY_BUF_SIZE); fails with "allocation failed: out of vmalloc space - use vmalloc= to increase size." (and there is no room or swap to increase that vmalloc= parameter). So, I would need to get a page from the kernel and fill the vmf->page field. How to allocate a page (I assume that the offset of the page is known, as it is vm->pgoff). What base memory should I use instead of my_buf? PS: I also did set up the vma->flags |= VM_NORESERVE; (in the my_mmap()), but not sure if it helps. Is there any vmalloc_user_unreserved()-like function? (let's say, lazy allocation) Also, writing 1 to /proc/sys/vm/overcommit_memory and large values (eg 500) to /proc/sys/vm/overcommit_ratio before trying to my_buf=vmalloc_user(<large_size>) didn't work.

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  • how to use iterator in c++?

    - by tsubasa
    I'm trying to calculate distance between 2 points. The 2 points I stored in a vector in c++: (0,0) and (1,1). I'm supposed to get results as 0 1.4 1.4 0 but the actual result that I got is 0 1 -1 0 I think there's something wrong with the way I use iterator in vector. Could somebody help? I posted the code below. typedef struct point { float x; float y; } point; float distance(point *p1, point *p2) { return sqrt((p1->x - p2->x)*(p1->x - p2->x) + (p1->y - p2->y)*(p1->y - p2->y)); } int main() { vector <point> po; point p1; p1.x=0; p1.y=0; point p2; p2.x=1; p2.y=1; po.push_back(p1); po.push_back(p2); vector <point>::iterator ii; vector <point>::iterator jj; for (ii=po.begin(); ii!=po.end(); ii++) { for (jj=po.begin(); jj!=po.end(); jj++) { cout<<distance(ii,jj)<<" "; } } return 0; }

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  • Presenting collection of structures of strings in grid or similar in WPF - Example? Ideas?

    - by Andrew
    Hi, I have a collection of structures. The structure is just some strings. Example public struct ReportLine { public string Name; public string Address; public string Phone; ...// about 10 other strings } I can't change this part. What I want to do is display it in a simple grid or simlar in WPF. My only requirements are: a) need column headers b) rows must alternate in color c) columns big enough to hold largest datum (which is not know until run time) Can someone point me to an example to get me started? Is the GridView the way to go? Or DataGrid? Or perhaps just the grid? I have the book Pro WPF in C# 2008 and it covers binding ListBox's to collections, but the collections always seem to be collections of one field (ex. a collection of 40 names). Here I have a collection (an array in fact) of a structure. How do I setup the databinding? As you can see, I'm new to this and probably would most benefit from a reference to an article. I've found articles covering collections of 1 field, but no examples covering binding to an array of structures. Also, my intitial research indicates c) can't be easily done, if you demand that the column is big enough for all the data in that column, not just the visible data. Thanks, dave

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  • Problem with "moveable-only types" in VC++ 2010

    - by Luc Touraille
    I recently installed Visual Studio 2010 Professional RC to try it out and test the few C++0x features that are implemented in VC++ 2010. I instantiated a std::vector of std::unique_ptr, without any problems. However, when I try to populate it by passing temporaries to push_back, the compiler complains that the copy constructor of unique_ptr is private. I tried inserting an lvalue by moving it, and it works just fine. #include <utility> #include <vector> int main() { typedef std::unique_ptr<int> int_ptr; int_ptr pi(new int(1)); std::vector<int_ptr> vec; vec.push_back(std::move(pi)); // OK vec.push_back(int_ptr(new int(2)); // compiler error } As it turns out, the problem is neither unique_ptr nor vector::push_back but the way VC++ resolves overloads when dealing with rvalues, as demonstrated by the following code: struct MoveOnly { MoveOnly() {} MoveOnly(MoveOnly && other) {} private: MoveOnly(const MoveOnly & other); }; void acceptRValue(MoveOnly && mo) {} int main() { acceptRValue(MoveOnly()); // Compiler error } The compiler complains that the copy constructor is not accessible. If I make it public, the program compiles (even though the copy constructor is not defined). Did I misunderstand something about rvalue references, or is it a (possibly known) bug in VC++ 2010 implementation of this feature?

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  • Why Does My Vector<PEVENTLOGRECORD> Mysteriously Get Cleared?

    - by Eric
    Hello everyone, I am making a program that reads and stores data from Windows EventLog files (.evt) in C++. I am using the calls OpenBackupEventLog(ServerName, FileName) and ReadEventLog(...). Also using this: PEVENTLOGRECORD Anyway, without supplying all of the code, here is the basic idea: 1. I get a handle to the .evt file using OpenBackupEventLog() and passing in a file name. 2. I then use ReadEventLog() to fill up a buffer with an unknown number of EventLog messages. 3. I traverse through the buffer and add each message to a vector 4. I keep filling up buffers (repeat steps 2 and 3) until I reach the end of the file. Here is my code for filling the vector: vector<PEVENTLOGRECORD> allRecords; while(_status == ERROR_SUCCESS) { if(!ReadEventLog(...)) CheckStatus(); else FillVectorFromBuffer(allRecords) } // Function FillVectorFromBuffer FillVectorFromBuffer(vector(PEVENTLOGRECORD) &allRecords) { int bytesExamined = 0; PBYTE pRecord = (PBYTE)_lpBuffer; // This is one of the params in ReadEventLog() while(bytesExamined < _pnBytesRead) // Another param from ReadEventLog { PEVENTLOGRECORD currentRecord = (PEVENTLOGRECORD)(pRecord); allRecords.push_back(currentRecord); pRecord += currentRecord->Length; bytesExamined += currentRecord->Length; } } Anyway, whenever I run this, it will get all the EventLogs in the file, and the vector will have everything I want it to. But as soon as this line: if(!ReadEventLog()) gets called and returns true (aka ReadEventLog() returns false), then every field in my vector gets set to zero. The vector will still contain the correct number of elements, it's just that all of the fields in the PEVENTLOGRECORD struct are now zero. Anyone with better debugging experience have any ideas? Thanks.

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  • How to use boost::fusion::transform on heterogeneous containers?

    - by Kyle
    Boost.org's example given for fusion::transform is as follows: struct triple { typedef int result_type; int operator()(int t) const { return t * 3; }; }; // ... assert(transform(make_vector(1,2,3), triple()) == make_vector(3,6,9)); Yet I'm not "getting it." The vector in their example contains elements all of the same type, but a major point of using fusion is containers of heterogeneous types. What if they had used make_vector(1, 'a', "howdy") instead? int operator()(int t) would need to become template<typename T> T& operator()(T& const t) But how would I write the result_type? template<typename T> typedef T& result_type certainly isn't valid syntax, and it wouldn't make sense even if it was, because it's not tied to the function.

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  • SFINAE + sizeof = detect if expression compiles

    - by FredOverflow
    I just found out how to check if operator<< is provided for a type. template<class T> T& lvalue_of_type(); template<class T> T rvalue_of_type(); template<class T> struct is_printable { template<class U> static char test(char(*)[sizeof( lvalue_of_type<std::ostream>() << rvalue_of_type<U>() )]); template<class U> static long test(...); enum { value = 1 == sizeof test<T>(0) }; typedef boost::integral_constant<bool, value> type; }; Is this trick well-known, or have I just won the metaprogramming Nobel prize? ;) EDIT: I made the code simpler to understand and easier to adapt with two global function template declarations lvalue_of_type and rvalue_of_type.

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  • Error_No_Token by adding printer driver (c#)

    - by user1686388
    I'm trying to add printer drivers using the windows API function AddPrinterDriver. The Win32 error 1008 (An attempt was made to reference a token that does not exist.) was always generated. My code is shown as following [DllImport("Winspool.drv")] static extern bool AddPrinterDriver(string Name, Int32 Level, [in] ref DRIVER_INFO_3 DriverInfo); [StructLayout(LayoutKind.Sequential)] public struct DRIVER_INFO_3 { public Int32 cVersion; public string Name; public string Environment; public string DriverPath; public string DataFile; public string ConfigFile; public string HelpFile; public string DependentFiles; public string MonitorName; public string DefaultDataType; } //....................... DRIVER_INFO_3 di = new DRIVER_INFO_3(); //...................... AddPrinterDriver(Environment.MachineName, 3, ref di); I have also tried to get a token by "ImpersonateSelf" before adding the printer driver. But the error 1008 insists. Does anyone have an idea? best regards.

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  • Regarding the ViewModel

    - by mizipzor
    Im struggling to understand the ViewModel part of the MVVM pattern. My current approach is to have a class, with no logic whatsoever (important), except that it implements INotifyPropertyChanged. The class is just a collection of properties, a struct if you like, describing an as small part of the data as possible. I consider this my Model. Most of the WPF code I write are settings dialogs that configure said Model. The code-behind of the dialog exposes a property which returns an instance of the Model. In the XAML code I bind to subproperties of that property, thereby binding directly to the Model's properties. Which works quite well since it implements the INotifyPropertyChanged. I consider this settings dialog the View. However, I havent really been able to figure out what in all this is the ViewModel. The articles Ive read suggests that the ViewModel should tie the View and the Model together, providing the logic the Model lacks but is still to complex to go directly into the View. Is this correct? Would, in my example, the code-behind of the settings dialog be considered the ViewModel? I just feel a bit lost and would like my peers to debunk some of my assumptions. Am I completely off track here?

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  • How slow are bit fields in C++

    - by Shane MacLaughlin
    I have a C++ application that includes a number of structures with manually controlled bit fields, something like #define FLAG1 0x0001 #define FLAG2 0x0002 #define FLAG3 0x0004 class MyClass { ' ' unsigned Flags; int IsFlag1Set() { return Flags & FLAG1; } void SetFlag1Set() { Flags |= FLAG1; } void ResetFlag1() { Flags &= 0xffffffff ^ FLAG1; } ' ' }; For obvious reasons I'd like to change this to use bit fields, something like class MyClass { ' ' struct Flags { unsigned Flag1:1; unsigned Flag2:1; unsigned Flag3:1; }; ' ' }; The one concern I have with making this switch is that I've come across a number of references on this site stating how slow bit fields are in C++. My assumption is that they are still faster than the manual code shown above, but is there any hard reference material covering the speed implications of using bit fields on various platforms, specifically 32bit and 64bit windows. The application deals with huge amounts of data in memory and must be both fast and memory efficient, which could well be why it was written this way in the first place.

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  • Nullable<T> as a parameter

    - by ferch
    I alredy have this: public static object GetDBValue(object ObjectEvaluated) { if (ObjectEvaluated == null) return DBNull.Value; else return ObjectEvaluated; } used like: List<SqlParameter> Params = new List<SqlParameter>(); Params.Add(new SqlParameter("@EntityType", GetDBValue(EntityType))); Now i wanted to keep the same interface but extend that to use it with nullable public static object GetDBValue(int? ObjectEvaluated) { if (ObjectEvaluated.HasValue) return ObjectEvaluated.Value; else return DBNull.Value; } public static object GetDBValue(DateTime? ObjectEvaluated) {...} but i want only 1 function GetDBValue for nullables. How do I do that and keep the call as is is? Is that possible at all? I can make it work like: public static object GetDBValue<T>(Nullable<T> ObjectEvaluated) where T : struct { if (ObjectEvaluated.HasValue) return ObjectEvaluated.Value; else return DBNull.Value; } But the call changes to: Params.Add(new SqlParameter("@EntityID ", GetDBValue<int>(EntityID)));

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  • Is it poor design to create objects that only execute code during the constructor?

    - by Curtix
    In my design I am using objects that evaluate a data record. The constructor is called with the data record and type of evaluation as parameters and then the constructor calls all of the object's code necessary to evaluate the record. This includes using the type of evaluation to find additional parameter-like data in a text file. There are in the neighborhood of 250 unique evaluation types that use the same or similar code and unique parameters coming from the text file. Some of these evaluations use different code so I benefit a lot from this model because I can use inheritance and polymorphism. Once the object is created there isn't any need to execute additional code on the object (at least for now) and it is used more like a struct; its kept on a list and 3 properties are used later. I think this design is the easiest to understand, code, and read. A logical alternative I guess would be using functions that return score structs, but you can't inherit from methods so it would make it kind of sloppy imo. I am using vb.net and these classes will be used in an asp.net web app as well as in a distributed app. thanks for your input

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  • MSVC 2003 doesn't see any definitions from a nested include file

    - by ezpresso
    I have a piece of code with COM class declaration as follows: #include "PathTypes.h" MIDL_INTERFACE("552C7555-0555-4444-BA86-56CF39AAFFFF") IPathCalc : public IUnknown { virtual HRESULT STDMETHODCALLTYPE GetLocation( /* [retval][out] */ GeoLocation* pLoc) = 0; virtual HRESULT STDMETHODCALLTYPE SetLocation( /* [in] */ GeoLocation* pLoc) = 0; ... }; Below is the contents of PathTypes.h file: #if !defined(PATHCALC_TYPES_INCLUDED) #define PATHCALC_TYPES_INCLUDED #include "libastro/AstronomyStructs.h" #endif And the libastro/AstronomyStructs.h from an external cross-platform library: #ifndef _ASTRONOMY_STRUCTS_INCLUDED #define _ASTRONOMY_STRUCTS_INCLUDED typedef struct { double lattitude; double longitude; } GeoLocation; ... #endif /* _ASTRONOMY_STRUCTS_INCLUDED */ When I'm trying to build this code with g++ everything goes well. That's not the case with MSVC 2003 which returns error C2061: syntax error : identifier 'GeoLocation'. Seems like MSVC doesn't "see" the definitions from the libastro/AstronomyStructs.h file. When I replace #include "PathTypes.h" with #include "libastro/AstronomyStructs.h" the code compiles without errors. How to make MSVC 2003 to actually "see" the definitions from the nested include files?

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  • How to use two parameters pointing to the same structure in one function ?

    - by ZaZu
    Hey guys, I have my code below that consits of a structure, a main, and a function. The function is supposed to display two parameters that have certain values, both of which point to the same structure. The problem I dont know how to add the SECOND parameter onto the following code : #include<stdio.h> #define first 500 #define sec 500 struct trial{ int f; int r; float what[first][sec]; }; int trialtest(trial *test); main(){ trial test; trialtest(&test); } int trialtest(trial *test){ int z,x,i; for(i=0;i<5;i++){ printf("%f,(*test).what[z][x]); } return 0; } I need to add a new parameter test_2 there (IN THE SAME FUNCTION) using this code : for(i=0;i<5;i++){ printf("%f,(*test_2).what[z][x]); How does int trialtest(trial *test) changes ? and how does it change in main ? I know that I should declare test_2 as well, like this : trial test,test_2; But what about passing the address in the function ? I do not need to edit it right ? trialtest(&test); --- This will remain the same ? So please, tell me how would I use test_2 as a parameter pointing to the same structure as test, both in the same function.. Thank you !! Please tell me if you need more clarification

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  • [C++] My First Go With Function Templates

    - by bobber205
    Thought it was pretty straight forward. But I get a "iterator not dereferencable" errro when running the below code. What's wrong? template<typename T> struct SumsTo : public std::binary_function<T, T, bool> { int myInt; SumsTo(int a) { myInt = a; } bool operator()(const T& l, const T& r) { cout << l << " + " << r; if ((l + r) == myInt) { cout << " does add to " << myInt; } else { cout << " DOES NOT add to " << myInt; } return true; } }; void main() { list<int> l1; l1.push_back(1); l1.push_back(2); l1.push_back(3); l1.push_back(4); list<int> l2; l2.push_back(9); l2.push_back(8); l2.push_back(7); l2.push_back(6); transform(l1.begin(), l1.end(), l2.begin(), l2.end(), SumsTo<int>(10) ); }

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  • BUG - ProteaAudio with Lua does not work

    - by Stackfan
    Any idea why i cant use or cant build in Lua the ProTeaAudio ? 1) Exist [root@example ~]# yum install lua-devel Loaded plugins: presto, refresh-packagekit Setting up Install Process Package lua-devel-5.1.4-4.fc12.i686 already installed and latest version Nothing to do 2) get failed to build the RtAudio [sun@example proteaAudio_src_090204]$ make g++ -O2 -Wall -DHAVE_GETTIMEOFDAY -D__LINUX_ALSA__ -Irtaudio -Irtaudio/include -I../lua/src -I../archive/baseCode/include -c rtaudio/RtAudio.cpp -o rtaudio/RtAudio.o rtaudio/RtAudio.cpp:365: error: no ‘unsigned int RtApi::getStreamSampleRate()’ member function declared in class ‘RtApi’ rtaudio/RtAudio.cpp: In member function ‘virtual bool RtApiAlsa::probeDeviceOpen(unsigned int, RtApi::StreamMode, unsigned int, unsigned int, unsigned int, RtAudioFormat, unsigned int*, RtAudio::StreamOptions*)’: rtaudio/RtAudio.cpp:5835: error: ‘RTAUDIO_SCHEDULE_REALTIME’ was not declared in this scope rtaudio/RtAudio.cpp:5837: error: ‘struct RtAudio::StreamOptions’ has no member named ‘priority’ make: *** [rtaudio/RtAudio.o] Error 1 [sun@example proteaAudio_src_090204]$ Lua 5.1.4 Copyright (C) 1994-2008 Lua.org, PUC-Rio > require("proAudioRt"); stdin:1: module 'proAudioRt' not found: no field package.preload['proAudioRt'] no file './proAudioRt.lua' no file '/usr/share/lua/5.1/proAudioRt.lua' no file '/usr/share/lua/5.1/proAudioRt/init.lua' no file '/usr/lib/lua/5.1/proAudioRt.lua' no file '/usr/lib/lua/5.1/proAudioRt/init.lua' no file './proAudioRt.so' no file '/usr/lib/lua/5.1/proAudioRt.so' no file '/usr/lib/lua/5.1/loadall.so' stack traceback: [C]: in function 'require' stdin:1: in main chunk [C]: ?

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  • Output problem in mysql query in MFC program

    - by D.Gaughan
    Im currently working on a small MFC program that outputs data from a mysql database. I can get output when im using an sql statement that does not contain any variable eg. select album from Artists; but when i try to use a variable the program compiles but i get no output eg. mysql_perform_query(conn,select album from Artists where artists = '"+m_search_edit"'") Here is the function for mysql_perform_query: MYSQL_RES* mysql_perform_query(MYSQL *conn, const char* query) { // send the query to the database if (mysql_query(conn, query)) { // printf("MySQL query error : %s\n", mysql_error(conn)); // exit(1); } return mysql_use_result(conn); } And here is the code block for outputting the data: struct connection_details mysqlD; mysqlD.server = "www.freesqldatabase.com"; // where the mysql database is mysqlD.user = "**********"; // the root user of mysql mysqlD.password = "***********"; // the password of the root user in mysql mysqlD.database = "***************"; // the databse to pick // connect to the mysql database conn = mysql_connection_setup(mysqlD); CStringA query; query.Format("select album from Artists where artist = '%s'", CT2CA(m_search_edit)); res = mysql_perform_query(conn, query); //res = mysql_perform_query (conn, "select distinct artist from Artists"); while((row = mysql_fetch_row(res)) != NULL){ CString str; UpdateData(); str = ("%s\n", row[0]); UpdateData(FALSE); m_list_control.AddString(str); } The m_search_edit variable is the variable for an edit box. I am using Visual Studio 2008 with one copy of this program unicode and one nonunicode, I also have a version built with VC++ 6. Any tips on how I can get output from the databse using the m_search_edit variable??

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  • Getting ellipses function parameters without an initial argument

    - by Tox1k
    So I've been making a custom parser for a scripting language, and I wanted to be able to pass only ellipses arguments. I don't need or want an initial variable, however Microsoft and C seem to want something else. FYI, see bottom for info. I've looked at the va_* definitions #define _crt_va_start(ap,v) ( ap = (va_list)_ADDRESSOF(v) + _INTSIZEOF(v) ) #define _crt_va_arg(ap,t) ( *(t *)((ap += _INTSIZEOF(t)) - _INTSIZEOF(t)) ) #define _crt_va_end(ap) ( ap = (va_list)0 ) and the part I don't want is the v in va_start. As a little background I'm competent in goasm and I know how the stack works so I know what's happening here. I was wondering if there is a way to get the function stack base without having to use inline assembly. Ideas I've had: #define im_va_start(ap) (__asm { mov [ap], ebp }) and etc... but really I feel like that's messy and I'm doing it wrong. struct function_table { const char* fname; (void)(*fptr)(...); unsigned char maxArgs; }; function_table mytable[] = { { "MessageBox", &tMessageBoxA, 4 } }; ... some function that sorts through a const char* passed to it to find the matching function in mytable and calls tMessageBoxA with the params. Also, the maxArgs argument is just so I can check that a valid number of parameters is being sent. I have personal reasons for not wanting to send it in the function, but in the meantime we can just say it's because I'm curious. This is just an example; custom libraries are what I would be implementing so it wouldn't just be calling WinAPI stuff. void tMessageBoxA(...) { // stuff to load args passed MessageBoxA(arg1, arg2, arg3, arg4); } I'm using the __cdecl calling convention and I've looked up ways to reliably get a pointer to the base of the stack (not the top) but I can't seem to find any. Also, I'm not worried about function security or typechecking.

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