Search Results

Search found 21184 results on 848 pages for 'oracle oracle vm templates'.

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 382/848 | < Previous Page | 378 379 380 381 382 383 384 385 386 387 388 389  | Next Page >

  • How to specialize template for type derived from particular type

    - by relaxxx
    I have class World which manages creation of object... After creation it calls afterCreation method and I the created object is user-defined type derived from Entity (eg. MyEntity), I want to call addEntity. I the object was something else, I want to do nothing. addEntity must be called with appropriate T, because it generates unique IDs for every derived class etc. Here is my solution: template <int v> struct ToType { enum { value = v }; }; template <typename T> void World::afterCreation(T * t) { afterCreation(t, ToType<std::is_base_of<Entity, T>::value>()); } template <typename T> void World::afterCreation(T * t, ToType<true>) { addEntity(t); //here I cant pass Entity *, I need the real type, eg. MyEntity } template <typename T> void World::afterCreation(T * t, ToType<false>) { } My question is - Can in be done better way? How can I simulate following code without ToType or similar? template <typename T> void afterCreation(){/*generic impl*/} template <typename T where T is derived from Entity> void afterCreation(){/*some specific stuff*/} "specialize" in the title is only to describe my intention, no need to solve problem with template specialization

    Read the article

  • Accept templated parameter of stl_container_type<string>::iterator

    - by Rodion Ingles
    I have a function where I have a container which holds strings (eg vector<string>, set<string>, list<string>) and, given a start iterator and an end iterator, go through the iterator range processing the strings. Currently the function is declared like this: template< typename ContainerIter> void ProcessStrings(ContainerIter begin, ContainerIter end); Now this will accept any type which conforms to the implicit interface of implementing operator*, prefix operator++ and whatever other calls are in the function body. What I really want to do is have a definition like the one below which explicitly restricts the amount of input (pseudocode warning): template< typename Container<string>::iterator> void ProcessStrings(Container<string>::iterator begin, Container<string>::iterator end); so that I can use it as such: vector<string> str_vec; list<string> str_list; set<SomeOtherClass> so_set; ProcessStrings(str_vec.begin(), str_vec.end()); // OK ProcessStrings(str_list.begin(), str_list.end()); //OK ProcessStrings(so_set.begin(), so_set.end()); // Error Essentially, what I am trying to do is restrict the function specification to make it obvious to a user of the function what it accepts and if the code fails to compile they get a message that they are using the wrong parameter types rather than something in the function body that XXX function could not be found for XXX class.

    Read the article

  • Link error for user defined class type template parameter

    - by isurulucky
    Hi, I implemented a Simple STL map in C++. Factored out the comparison as a type as I was instructed to, then implemented the comparison as shown below: template <typename T> int KeyCompare<T>::operator () (T tKey1, T tKey2) { if(tKey1 < tKey2) return -1; else if(tKey1 > tKey2) return 1; else return 0; } here, tKey1 and tKet2 are the two keys I'm comparing. This worked well for all the basic data types and string. I added a template specialization to compare keys of a user defined type named Test and added a specialization as follows: int KeyCompare<Test>::operator () (Test tKey1, Test tKey2) { if(tKey1.a < tKey2.a) return -1; else if(tKey1.a > tKey2.a) return 1; else return 0; } when I run this, I get a linking error saying SimpleMap.obj : error LNK2005: "public: int __thiscall KeyCompare::operator()(class Test,class Test)" (??R?$KeyCompare@VTest@@@@QAEHVTest@@0@Z) already defined in MapTest.obj SimpleMap.obj : error LNK2005: "public: __thiscall KeyCompare::~KeyCompare(void)" (??1?$KeyCompare@VTest@@@@QAE@XZ) already defined in MapTest.obj SimpleMap.obj : error LNK2005: "public: __thiscall KeyCompare::KeyCompare(void)" (??0?$KeyCompare@VTester@@@@QAE@XZ) already defined in MapTest.obj MapTest.cpp is the test harness class in which I wrote the test case. I have used include guards as well, to stop multiple inclusions. Any idea what the matter is?? Thank you very much!!

    Read the article

  • "Ambiguous template specialization" problem

    - by Setien
    I'm currently porting a heap of code that has previously only been compiled with Visual Studio 2008. In this code, there's an arrangement like this: template <typename T> T convert( const char * s ) { // slow catch-all std::istringstream is( s ); T ret; is >> ret; return ret; } template <> inline int convert<int>( const char * s ) { return (int)atoi( s ); } Generally, there are a lot of specializations of the templated function with different return types that are invoked like this: int i = convert<int>( szInt ); The problem is, that these template specializations result in "Ambiguous template specialization". If it was something besides the return type that differentiated these function specializations, I could obviously just use overloads, but that's not an option. How do I solve this without having to change all the places the convert functions are called?

    Read the article

  • How do polymorphic inline caches work with mutable types?

    - by kingkilr
    A polymorphic inline cache works by caching the actual method by the type of the object, in order to avoid the expensive lookup procedures (usually a hashtable lookup). How does one handle the type comparison if the type objects are mutable (i.e. the method might be monkey patched into something different at run time). The one idea I've come up with would be a "class counter" that gets incremented each time a method is adjusted, however this seems like it would be exceptionally expensive in a heavily monkey patched environ since it would kill all the PICs for that class, even if the methods for them weren't altered. I'm sure there must be a good solution to this, as this issue is directly applicable to Javascript and AFAIK all 3 of the big JS VMs have PICs (wow acronym ahoy).

    Read the article

  • VB.NET template instance - passing a variable data type

    - by FerretallicA
    As the title suggests, I'm tyring to pass a variable data type to a template class. Something like this: frmExample = New LookupForm(Of Models.MyClass) 'Works fine Dim SelectedType As Type = InstanceOfMyClass.GetType() 'Works fine repoGeneric = New Repositories.Repository(Of SelectedType) 'Ba-bow! repoGeneric = New Repositories.Repository(Of InstanceOfMyClass.GetType()) 'Ba-bow! I'm assuming it's something to do with the template being processed at compile time but even if I'm off the mark there, it wouldn't solve my problem anyway. I can't find any relevant information on using Reflection to instance template classes either. (How) can I create an instance of a dynamically typed repository at runtime?

    Read the article

  • ASP.NET MVC editor template for property

    - by Idsa
    Usually I render my forms by @Html.RenderModel, but this time I have a complex rendering logic and I render it manually. I decided to create a editor template for one property. Here is the code (copy pasted from default object editor template implementation): <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> <% var modelMetadata = ViewData.ModelMetadata; %> <% if (modelMetadata.HideSurroundingHtml) { %> <%= Html.Editor(modelMetadata.PropertyName) %> <% } else { %> <% if (!String.IsNullOrEmpty(Html.Label(modelMetadata.PropertyName).ToHtmlString())) { %> <div class="editor-label"><%= Html.Label(modelMetadata.PropertyName) %></div> <% } %> <div class="editor-field"> <%= Html.Editor(modelMetadata.PropertyName) %> <%= Html.ValidationMessage(modelMetadata.PropertyName) %> </div> <% } %> And here is how I use it: @Html.EditorFor(x => x.SomeProperty, "Property") //"Property" is template above But it didn't work: labels are rendered regardless of DisplayName and editors are not rendered at all (in Watches Html.Editor(modelMetadata.PropertyName shows empty string). What am I doing wrong?

    Read the article

  • C++ string template library

    - by Gopalakrishnan Subramani
    I want simple C++ string based template library to replace strings at runtime. For example, I will use string template = "My name is {{name}}"; At runtime, I want the name to be changed based on actual one. I found one example, www.stringtemplate.org but I little scared when its talks about antlr etc.

    Read the article

  • Detecting const-ness of nested type

    - by Channel72
    Normally, if I need to detect whether a type is const I just use boost::is_const. However, I ran into trouble when trying to detect the const-ness of a nested type. Consider the following traits template, which is specialized for const types: template <class T> struct traits { typedef T& reference; }; template <class T> struct traits<const T> { typedef T const& reference; }; The problem is that boost::is_const doesn't seem to detect that traits<const T>::reference is a const type. For example: std::cout << std::boolalpha; std::cout << boost::is_const<traits<int>::reference>::value << " "; std::cout << boost::is_const<traits<const int>::reference>::value << std::endl; This outputs: false false Why doesn't it output false true?

    Read the article

  • Partial template specialization for more than one typename

    - by Matt Joiner
    In the following code, I want to consider functions (Ops) that have void return to instead be considered to return true. The type Retval, and the return value of Op are always matching. I'm not able to discriminate using the type traits shown here, and attempts to create a partial template specialization based on Retval have failed due the presence of the other template variables, Op and Args. How do I specialize only some variables in a template specialization without getting errors? Is there any other way to alter behaviour based on the return type of Op? template <typename Retval, typename Op, typename... Args> Retval single_op_wrapper( Retval const failval, char const *const opname, Op const op, Cpfs &cpfs, Args... args) { try { CallContext callctx(cpfs, opname); Retval retval; if (std::is_same<bool, Retval>::value) { (callctx.*op)(args...); retval = true; } else { retval = (callctx.*op)(args...); } assert(retval != failval); callctx.commit(cpfs); return retval; } catch (CpfsError const &exc) { cpfs_errno_set(exc.fserrno); LOGF(Info, "Failed with %s", cpfs_errno_str(exc.fserrno)); } return failval; }

    Read the article

  • How do you return a pointer to a base class with a virtual function?

    - by Nick Sweet
    I have a base class called Element, a derived class called Vector, and I'm trying to redefine two virtual functions from Element in Vector. //element.h template <class T> class Element { public: Element(); virtual Element& plus(const Element&); virtual Element& minus(const Element&); }; and in another file //Vector.h #include "Element.h" template <class T> class Vector: public Element<T> { T x, y, z; public: //constructors Vector(); Vector(const T& x, const T& y = 0, const T& z =0); Vector(const Vector& u); ... //operations Element<T>& plus(const Element<T>& v) const; Element<T>& minus(const Element<T>& v) const; ... }; //sum template <class T> Element<T>& Vector<T>::plus(const Element<T>& v) const { Element<T>* ret = new Vector((x + v.x), (y + v.y), (z + v.z)); return *ret; } //difference template <class T> Element<T>& Vector<T>::minus(const Element<T>& v) const { Vector<T>* ret = new Vector((x - v.x), (y - v.y), (z - v.z)); return *ret; } but I always get error: 'const class Element' has no member named 'getx' So, can I define my virtual functions to take Vector& as an argument instead, or is there a way for me to access the data members of Vector through a pointer to Element? I'm still fairly new to inheritance polymorphism, fyi.

    Read the article

  • C# generics when T could be an array

    - by bufferz
    I am writing a C# wrapper for a 3rd party library that reads both single values and arrays from a hardware device, but always returns an object[] array even for one value. This requires repeated calls to object[0] when I'd like the end user to be able to use generics to receive either an array or single value. I want to use generics so the callee can use the wrapper in the following ways: MyWrapper<float> mw = new MyWrapper<float>( ... ); float value = mw.Value; //should return float; MyWrapper<float[]> mw = new MyWrapper<float[]>( ... ); float[] values = mw.Value; //should return float[]; In MyWrapper I have the Value property currently as the following: public T Value { get { if(_wrappedObject.Values.Length > 1) return (T)_wrappedObject.Value; //T could be float[]. this doesn't compile. else return (T)_wrappedObject.Values[0]; //T could be float. this compiles. } } I get a compile error in the first case: Cannot convert type 'object[]' to 'T' If I change MyWrapper.Value to T[] I receive: Cannot convert type 'object[]' to 'T[]' Any ideas of how to achieve my goal? Thanks!

    Read the article

  • Using member variables inherited from a templated base class (C++)

    - by Aaron Becker
    I'm trying to use member variables of a templated base class in a derived class, as in this example: template <class dtype> struct A { int x; }; template <class dtype> struct B : public A<dtype> { void test() { int id1 = this->x; // always works int id2 = A<dtype>::x; // always works int id3 = B::x; // always works int id4 = x; // fails in gcc & clang, works in icc and xlc } }; gcc and clang are both very picky about using this variable, and require either an explicit scope or the explicit use of "this". With some other compilers (xlc and icc), things work as I would expect. Is this a case of xlc and icc allowing code that's not standard, or a bug in gcc and clang?

    Read the article

  • Linking a template class using another template class (error LNK2001)

    - by Luís Guilherme
    I implemented the "Strategy" design pattern using an Abstract template class, and two subclasses. Goes like this: template <class T> class Neighbourhood { public: virtual void alter(std::vector<T>& array, int i1, int i2) = 0; }; and template <class T> class Swap : public Neighbourhood<T> { public: virtual void alter(std::vector<T>& array, int i1, int i2); }; There's another subclass, just like this one, and alter is implemented in the cpp file. Ok, fine! Now I declare another method, in another class (including neighbourhood header file, of course), like this: void lSearch(/*parameters*/, Neighbourhood<LotSolutionInformation> nhood); It compiles fine and cleanly. When starting to link, I get the following error: 1>SolverFV.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall lsc::Neighbourhood<class LotSolutionInformation>::alter(class std::vector<class LotSolutionInformation,class std::allocator<class LotSolutionInformation> > &,int,int)" (?alter@?$Neighbourhood@VLotSolutionInformation@@@lsc@@UAEXAAV?$vector@VLotSolutionInformation@@V?$allocator@VLotSolutionInformation@@@std@@@std@@HH@Z)

    Read the article

  • Django 1.1 template question

    - by Bovril
    Hi All, I'm a little stuck trying to get my head around a django template. I have 2 objects, a cluster and a node I would like a simple page that lists... [Cluster 1] [associated node 1] [associated node 2] [associated node 3] [Cluster 2] [associated node 4] [associated node 5] [associated node 6] I've been using Django for about 2 days so if i've missed the point, please be gentle :) Models - class Node(models.Model): name = models.CharField(max_length=30) description = models.TextField() cluster = models.ForeignKey(Cluster) def __unicode__(self): return self.name class Cluster(models.Model): name = models.CharField(max_length=30) description = models.TextField() def __unicode__(self): return self.name Views - def DSAList(request): clusterlist = Cluster.objects.all() nodelist = Node.objects.all() t = loader.get_template('dsalist.html') v = Context({ 'CLUSTERLIST' : clusterlist, 'NODELIST' : nodelist, }) return HttpResponse(t.render(v)) Template - <body> <TABLE> {% for cluster in CLUSTERLIST %} <tr> <TD>{{ cluster.name }}</TD> {% for node in NODELIST %} {% if node.cluster.id == cluster.id %} <tr> <TD>{{ node.name }}</TD> </tr> {% endif %} {% endfor %} </tr> {% endfor %} </TABLE> </body> Any ideas ?

    Read the article

  • WPF DataGridRow Template - how to achieve Selected event

    - by user1809972
    I would like to override the DataGridRow template depending on the datatype of object bound to the grid. If the type is label, it just shows a Label. Otehrwise, it shows the cells. Follwing is the xaml. <DataTrigger Binding="{Binding Path=IsLabel, UpdateSourceTrigger=PropertyChanged}" Value="True"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type DataGridRow}"> <Grid> <Label HorizontalAlignment="Center" Padding="3,3,3,3" FontWeight="Bold" Content="{Binding Id}"/> </Grid> </ControlTemplate> </Setter.Value> </Setter> </DataTrigger> The grid looks ok. But, when the Label is clicked, it doesnt raise the Selection changed event for the DataGridRow. How do I achieve this behaviour? This label should just behave as any other DataGridRow(with the default template). Thanks

    Read the article

  • "Inherited" types in C++

    - by Ken Moynihan
    The following code does not compile. I get an error message: error C2039: 'Asub' : is not a member of 'C' Can someone help me to understand this? Tried VS2008 & 2010 compiler. template <class T> class B { typedef int Asub; public: void DoSomething(typename T::Asub it) { } }; class C : public B<C> { public: typedef int Asub; }; class A { public: typedef int Asub; }; int _tmain(int argc, _TCHAR* argv[]) { C theThing; theThing.DoSomething(C::Asub()); return 0; }

    Read the article

  • When a template is rendered in template tag code, MEDIA_URL is not in context

    - by culebrón
    I want to use a template for 2 template tags. In the template, I used {{ MEDIA_URL }} and discovered that MEDIA_URL is not in context as expected. Had to use get_config and pass it manually. Why is the setting not in context, how else can I put it there, or maybe there's a better way that a template tag? (include, etc?) from django.template import Library from apps.annoying.functions import get_config from django.template.loader import render_to_string register = Library() @register.simple_tag def next_in_gallery(photo, gallery): next = photo.get_next_in_gallery(gallery) return make_arrow('right', next) @register.simple_tag def previous_in_gallery(photo, gallery): prev = photo.get_previous_in_gallery(gallery) return make_arrow('left', prev) def make_arrow(direction, object): return render_to_string('myapp/arrow.html', {'direction': direction, 'object': object, 'MEDIA_URL': get_config('MEDIA_URL', '')})

    Read the article

  • Specializating a template function that takes a universal reference parameter

    - by David Stone
    How do I specialize a template function that takes a universal reference parameter? foo.hpp: template<typename T> void foo(T && t) // universal reference parameter foo.cpp template<> void foo<Class>(Class && class) { // do something complicated } Here, Class is no longer a deduced type and thus is Class exactly; it cannot possibly be Class &, so reference collapsing rules will not help me here. I could perhaps create another specialization that takes a Class & parameter (I'm not sure), but that implies duplicating all of the code contained within foo for every possible combination of rvalue / lvalue references for all parameters, which is what universal references are supposed to avoid. Is there some way to accomplish this? To be more specific about my problem in case there is a better way to solve it: I have a program that can connect to multiple game servers, and each server, for the most part, calls everything by the same name. However, they have slightly different versions for a few things. There are a few different categories that these things can be: a move, an item, etc. I have written a generic sort of "move string to move enum" set of functions for internal code to call, and my server interface code has similar functions. However, some servers have their own internal ID that they communicate with, some use strings, and some use both in different situations. Now what I want to do is make this a little more generic. I want to be able to call something like ServerNamespace::server_cast<Destination>(source). This would allow me to cast from a Move to a std::string or ServerMoveID. Internally, I may need to make a copy (or move from) because some servers require that I keep a history of messages sent. Universal references seem to be the obvious solution to this problem. The header file I'm thinking of right now would expose simply this: namespace ServerNamespace { template<typename Destination, typename Source> Destination server_cast(Source && source); } And the implementation file would define all legal conversions as template specializations.

    Read the article

  • C++ meta-splat function

    - by aaa
    hello. Is there an existing function (in boost mpl or fusion) to splat meta-vector to variadic template arguments? for example: splat<vector<T1, T2, ...>, function>::type same as function<T1, T2, ...> my search have not found one, and I do not want to reinvent one if it already exists. edit: after some tinkering, apparently it's next to impossible to accomplish this in general way, as it would require declaring full template template parameter list for all possible cases. only reasonable solution is to use macro: #define splat(name, function) \ template<class T, ...> struct name; \ template<class T> \ struct name<T,typename boost::enable_if_c< \ result_of::size<T>::value == 1>::type> { \ typedef function< \ typename result_of::value_at_c<T,0>::type \ > type; \ }; Oh well. thank you

    Read the article

  • Type parameterization in Scala

    - by horatius83
    So I'm learning Scala at the moment, and I'm trying to create an abstract vector class with a vector-space of 3 (x,y,z coordinates). I'm trying to add two of these vectors together with the following code: package math class Vector3[T](ax:T,ay:T,az:T) { def x = ax def y = ay def z = az override def toString = "<"+x+", "+y+", "+z+">" def add(that: Vector3[T]) = new Vector3(x+that.x, y+that.y, z+that.z) } The problem is I keep getting this error: error: type mismatch; found : T required: String def add(that: Vector3[T]) = new Vector3(x+that.x, y+that.y, z+that.z) I've tried commenting out the "toString" method above, but that doesn't seem to have any effect. Can anyone tell me what I'm doing wrong?

    Read the article

  • Do I need multiple template specializations if I want to specialize for several kinds of strings?

    - by romkyns
    For example: template<typename T> void write(T value) { mystream << value; } template<> void write<const char*>(const char* value) { write_escaped(mystream, value); } template<> void write<char*>(char* value) { write_escaped(mystream, value); } template<> void write<std::string>(std::string value) { write_escaped(mystream.c_str(), value); } This looks like I'm doing it wrong, especially the two variants for const and non-const char*. However I checked that if I only specialize for const char * then passing a char * variable will invoke the non-specialized version, when called like this in VC++10: char something[25]; strcpy(something, "blah"); write(something); What would be the proper way of doing this?

    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 | 378 379 380 381 382 383 384 385 386 387 388 389  | Next Page >