Search Results

Search found 2666 results on 107 pages for 'boost lambda'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 11/107 | < Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18  | Next Page >

  • To Reference A Generic Method With A Lambda Expression

    - by SDReyes
    It is possible to reference a generic method using a Lambda Expression Object? For example, having: TheObject: public abstract class LambdaExpression : Expression TheMethod (an extension method of LINQ): public static TSource Last<TSource>( this IEnumerable<TSource> source ) I'm trying to create an instance of TheObject, that references to TheMethod. How do you do such thing?

    Read the article

  • Rewriting a statement using LAMBDA(C#)

    - by Thinking
    Is it possible to write the folowing using lambda(C#) private static void GetRecordList(List<CustomerInfo> lstCustinfo) { for (int i = 1; i <= 5; i++) { if (i % 2 == 0) lstCustinfo.Add(new CustomerInfo { CountryCode = "USA", CustomerAddress = "US Address" + i.ToString(), CustomerName = "US Customer Name" + i.ToString(), ForeignAmount = i * 50 }); else lstCustinfo.Add(new CustomerInfo { CountryCode = "UK", CustomerAddress = "UK Address" + i.ToString(), CustomerName = "UK Customer Name" + i.ToString(), ForeignAmount = i * 80 }); } }

    Read the article

  • Lambda Expressions and Memory Management

    - by Surya
    How do the Lambda Expressions / Closures in C++0x complicate the memory management in C++? Why do some people say that closures have no place in languages with manual memory management? Is there claim valid and if yes, what are the reasons behind it?

    Read the article

  • using lambda instead of let in scheme

    - by Radagaisus
    Hey, In SICP 1.2.1 there is a function that makes a rational number, as follow: (define (make-rat n d) (let ((g (gcd n d))) (cons (/ n g) (/ d g)))) I'm just curious how you can implement the same thing using lambda instead of let, without calling GCD twice. I couldn't figure it out myself.

    Read the article

  • Lambda functions

    - by Oden
    Hey, I'm really interested in the way of using lambda functions. Does it make sense to use them in a high-level programming language? If yes, why? Is this really just a function embedded in a function (like this) or is there more behind?

    Read the article

  • Lambda recursive PHP functions.

    - by Kendall Hopkins
    Is it possible to have a PHP function that is both recursive and anonymous (lambda). This is my attempt to get it to work, but it doesn't pass in the function name. $factorial = function( $n ) use ( $factorial ) { if( $n == 1 ) return 1; return $factorial( $n - 1 ) * $n; }; print $factorial( 5 ); I'm also aware that this is a bad way to implement factorial, it's just an example.

    Read the article

  • Perfect Forwarding to async lambda

    - by Alexander Kondratskiy
    I have a function template, where I want to do perfect forwarding into a lambda that I run on another thread. Here is a minimal test case which you can directly compile: #include <thread> #include <future> #include <utility> #include <iostream> #include <vector> /** * Function template that does perfect forwarding to a lambda inside an * async call (or at least tries to). I want both instantiations of the * function to work (one for lvalue references T&, and rvalue reference T&&). * However, I cannot get the code to compile when calling it with an lvalue. * See main() below. */ template <typename T> std::string accessValueAsync(T&& obj) { std::future<std::string> fut = std::async(std::launch::async, [](T&& vec) mutable { return vec[0]; }, std::forward<T>(obj)); return fut.get(); } int main(int argc, char const *argv[]) { std::vector<std::string> lvalue{"Testing"}; // calling with what I assume is an lvalue reference does NOT compile std::cout << accessValueAsync(lvalue) << std::endl; // calling with rvalue reference compiles std::cout << accessValueAsync(std::move(lvalue)) << std::endl; // I want both to compile. return 0; } For the non-compiling case, here is the last line of the error message which is intelligible: main.cpp|13 col 29| note: no known conversion for argument 1 from ‘std::vector<std::basic_string<char> >’ to ‘std::vector<std::basic_string<char> >&’ I have a feeling it may have something to do with how T&& is deduced, but I can't pinpoint the exact point of failure and fix it. Any suggestions? Thank you! EDIT: I am using gcc 4.7.0 just in case this could be a compiler issue (probably not)

    Read the article

  • check that int array contains !=0 value using lambda

    - by netmajor
    hey, I have two-dimension array List<List<int>> boardArray How can I enumerate throw this array to check that it contains other value than 0 ? I think about boardArray.Contains and ForEach ,cause it return bool value but I don't have too much experience with lambda expression :/ Please help :)

    Read the article

  • boost::filesystem - how to create a boost path from a windows path string on posix plattforms?

    - by VolkA
    I'm reading path names from a database which are stored as relative paths in Windows format, and try to create a boost::filesystem::path from them on a Unix system. What happens is that the constructor call interprets the whole string as the filename. I need the path to be converted to a correct Posix path as it will be used locally. I didn't find any conversion functions in the boost::filesystem reference, nor through google. Am I just blind, is there an obvious solution? If not, how would you do this? Example: std::string win_path("foo\\bar\\asdf.xml"); std::string posix_path("foo/bar/asdf.xml"); // loops just once, as part is the whole win_path interpreted as a filename boost::filesystem::path boost_path(win_path); BOOST_FOREACH(boost::filesystem::path part, boost_path) { std::cout << part << std::endl; } // prints each path component separately boost::filesystem::path boost_path_posix(posix_path); BOOST_FOREACH(boost::filesystem::path part, boost_path_posix) { std::cout << part << std::endl; }

    Read the article

  • wrapping boost::ublas with swig

    - by leon
    I am trying to pass data around the numpy and boost::ublas layers. I have written an ultra thin wrapper because swig cannot parse ublas' header correctly. The code is shown below #include <boost/numeric/ublas/vector.hpp> #include <boost/numeric/ublas/matrix.hpp> #include <boost/lexical_cast.hpp> #include <algorithm> #include <sstream> #include <string> using std::copy; using namespace boost; typedef boost::numeric::ublas::matrix<double> dm; typedef boost::numeric::ublas::vector<double> dv; class dvector : public dv{ public: dvector(const int rhs):dv(rhs){;}; dvector(); dvector(const int size, double* ptr):dv(size){ copy(ptr, ptr+sizeof(double)*size, &(dv::data()[0])); } ~dvector(){} }; with the SWIG interface that looks something like %apply(int DIM1, double* INPLACE_ARRAY1) {(const int size, double* ptr)} class dvector{ public: dvector(const int rhs); dvector(); dvector(const int size, double* ptr); %newobject toString; char* toString(); ~dvector(); }; I have compiled them successfully via gcc 4.3 and vc++9.0. However when I simply run a = dvector(array([1.,2.,3.])) it gives me a segfault. This is the first time I use swigh with numpy and not have fully understanding between the data conversion and memory buffer passing. Does anyone see something obvious I have missed? I have tried to trace through with a debugger but it crashed within the assmeblys of python.exe. I have no clue if this is a swig problem or of my simple wrapper. Anything is appreciated.

    Read the article

  • Boost thread synchronization in release build

    - by Joseph16
    Hi, when I try to run the following code in debug and release mode in VS2005. Each time I see different output in console and It doesn't seem like the multithreading is achieved in release mode. 1. #include <boost/thread.hpp> 2. #include <iostream> 3. 4. void wait(int seconds) 5. { 6. boost::this_thread::sleep(boost::posix_time::seconds(seconds)); 7. } 8. 9. boost::mutex mutex; 10. 11. void thread() 12. { 13. for (int i = 0; i < 5; ++i) 14. { 15. //wait(1); 16. mutex.lock(); 17. std::cout << "Thread " << boost::this_thread::get_id() << ": " << i << std::endl; 18. mutex.unlock(); 19. } 20. } 21. 22. int main() 23. { 24. boost::thread t1(thread); 25. boost::thread t2(thread); 26. t1.join(); 27. t2.join(); 28. } Debug Mode Thread 00153E60: 0 Thread 00153E90: 0 Thread 00153E60: 1 Thread 00153E90: 1 Thread 00153E90: 2 Thread 00153E60: 2 Thread 00153E90: 3 Thread 00153E60: 3 Thread 00153E60: 4 Thread 00153E90: 4 Press any key to continue . . . Release Mode Thread 00153D28: 0 Thread 00153D28: 1 Thread 00153D28: 2 Thread 00153D28: 3 Thread 00153D28: 4 Thread 00153D58: 0 Thread 00153D58: 1 Thread 00153D58: 2 Thread 00153D58: 3 Thread 00153D58: 4 Press any key to continue . . .

    Read the article

  • Why boost property tree write_json saves everything as string? Is it possible to change that?

    - by pprzemek
    I'm trying to serialize using boost property tree write_json, it saves everything as strings, it's not that data are wrong, but I need to cast them explicitly every time and I want to use them somewhere else. (like in python or other C++ json (non boost) library) here is some sample code and what I get depending on locale: boost::property_tree::ptree root, arr, elem1, elem2; elem1.put<int>("key0", 0); elem1.put<bool>("key1", true); elem2.put<float>("key2", 2.2f); elem2.put<double>("key3", 3.3); arr.push_back( std::make_pair("", elem1) ); arr.push_back( std::make_pair("", elem2) ); root.put_child("path1.path2", arr); std::stringstream ss; write_json(ss, root); std::string my_string_to_send_somewhare_else = ss.str(); and my_string_to_send_somewhere_else is sth. like this: { "path1" : { "path2" : [ { "key0" : "0", "key1" : "true" }, { "key2" : "2.2", "key3" : "3.3" } ] } } Is there anyway to save them as the values, like: "key1" : true or "key2" : 2.2 ?

    Read the article

  • C# Lambda Expression Speed

    - by Nathan
    I have not used many lambda expressions before and I ran into a case where I thought I could make slick use of one. I have a custom list of ~19,000 records and I need to find out if a record exists or not in the list so instead of writing a bunch of loops or using linq to go through the list I decided to try this: for (int i = MinX; i <= MaxX; ++i) { tempY = MinY; while (tempY <= MaxY) { bool exists = myList.Exists(item => item.XCoord == i && item.YCoord == tempY); ++tempY; } } Only problem is it take ~9 - 11 seconds to execute. Am I doing something wrong is this just a case of where I shouldn't be using an expression like this? Thanks.

    Read the article

  • LINQ query and lambda expressions

    - by user329269
    I'm trying to write a LINQ query and am having problems. I'm not sure if lambda expressions are the answer or not but I think they may be. I have two combo boxes on my form: "State" and "Color". I want to select Widgets from my database based on the values of these two dropdowns. My widgets can be in one of the following states: Not Started, In Production, In Finishing, In Inventory, Sold. Widgets can have any color in the 'color' table in the database. The 'state' combobox has selections "Not Sold," "In Production/Finishing", "Not Started," "In Production," "In Finishing," "In Inventory," "Sold." (I hope these are self-explanatory.) The 'color' dropdown has "All Colors," and a separate item for each color in the database. How can I create a LINQ query to select the widgets I want from the database based on the dropdowns?

    Read the article

  • Problem with nested lambda expressions.

    - by Lehto
    Hey I'm trying to do a nested lambda expression like to following: textLocalizationTable.Where( z => z.SpokenLanguage.Any( x => x.FromCulture == "en-GB") ).ToList(); but i get the error: Member access 'System.String FromCulture' of 'DomainModel.Entities.SpokenLanguage' not legal on type 'System.Data.Linq.EntitySet`1[DomainModel.Entities.SpokenLanguage]. TextLocalization has this relation to spokenlanguage: [Association(OtherKey = "LocalizationID", ThisKey = "LocalizationID", Storage = "_SpokenLanguage")] private EntitySet<SpokenLanguage> _SpokenLanguage = new EntitySet<SpokenLanguage>(); public EntitySet<SpokenLanguage> SpokenLanguage { set { _SpokenLanguage = value; } get { return _SpokenLanguage; } } Any idea what is wrong?

    Read the article

  • .NET C# setting the value of a field defined by a lambda selector

    - by Frank Michael Kraft
    I have a generic class HierarchicalBusinessObject. In the constructor of the class I pass a lambda expression that defines a selector to a field of TModel. protected HierarchicalBusinessObject (Expression<Func<TModel,string>> parentSelector) A call would look like this, for example: public class WorkitemBusinessObject : HierarchicalBusinessObject<Workitem,WorkitemDataContext> { public WorkitemBusinessObject() : base(w => w.SuperWorkitem, w => w.TopLevel == true) { } } I am able to use the selector for read within the class. For example: sourceList.Select(_parentSelector.Compile()).Where(... Now I am asking myself how I could use the selector to set a value to the field. Something like selector.Body() .... Field...

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18  | Next Page >