C++ :: Detect Whether Or Not A Template Type Has A Protected Destructor?
Mar 28, 2014
Is there a way to detect whether or not a template type has a protected destructor?
I see there is std::is_destructible in C++11, but I can't tell if this will return true or false for the protected case. Also, I'm interested in finding a solution for C++03 as well.
/** This class build the singleton design pattern. Here you have full control over construction and deconstruction of the object. */ template<class T> class Singleton
[Code]....
I am getting error at the assertion points when i call to the class as follows:
I would like to use my own template type. I have class Fraction that saves fractions, and class Sample(the template class) that arrange fractions in order.
test.cpp: In function ‘int main()’: test.cpp:20:30: error: no matching function for call to ‘func1(std::vector<int>&)’ test.cpp:20:30: note: candidate is: test.cpp:8:45: note: template<class T, class U> std::map<T, T> func1(U) test.cpp:8:45: note: template argument deduction/substitution failed: test.cpp:20:30: note: couldn't deduce template parameter ‘T’
is there a way to have a template class respond to missing stuff in a template type ?
Code: template <typename Type> class MyClass { public: enum { ID = Type::ID }; // revert to 1 if Type::ID doesn't exist. };
If the Type passed to the template has an ID member (required to be an enum or a static const int), use it, if it is missing revert to a default value.
I can use this as a simplified way of configuring how MyClass works, without requiring Type to explicitely needing to define what it doesn't care about.
It needs to be resolved at compiletime, as it determines the number of elements in member array variables.
I have a class "Result" with a single template function Set(const std::string& arName, T& val) and a specialization of this function Set<Real>(const std::string& arName, Real& val) where Real is a typedef for double. The class is in a shared library and I use it in my main program. If I do result->Set<GLOBAL::Real>("U", 100.0); the wrong template function is called!
I check this by the output with std::cout.
Maybe it's a problem with the typedef.
If I link the object file of the Result class directly to my main program (no shared library), it works.
I don't understand why my compiler gives me this error when I'm trying to run this code:
Code:
#include <iostream> #include <cmath> using namespace std; class Airplane { public: Airplane(); ~Airplane();
[Code]...
The variable is protected. Yeah, that's right. But shouldn't a derived class be able to reach it? Or is it only in a function that the derived class is able to reach protected variables and isn't able to reach protected variables in the constructor?
I am doing C++ data structures exercises, and I am still learning some of the more basic concepts. I have a parent class:
template<class T> class linkedListType { public: protected: int count; nodeType<T> *first; nodeType<T> *last; private: };
Derived class:
#include "linkedListType.h" template<class T> class orderedLinkedList: public linkedListType<T> { public: void mergeList(orderedLinkedList<T> &list1, orderedLinkedList<t> &list2) { first = list1.first; ... } private: };
There is more code in my mergeList() function, but I included the line that is giving me problems. The error that my CodeBlocks compiler is giving me is that 'first' was not declared in this scope.
Strangely enough, if I change it to this->first, the error disappears.
1. Why does it not recognise 'first'? 2. Why would this->first work at all? Is the 'this' object a smart pointer?
I mainly code plugins for Cinema 4D .... I used to code in COFFEE (a javascript like language, only for Cinema 4D) and python. But, recently, I started coding in C++.
I start my development on a Mac, using Xcode. But then, to generate Windows versions of my plugins, I take my source code to Visual Studio, perform the necessary adjustments, and create Win32 and Win64 code.
Lately, I was trying to devise a scheme to protect my plugins from being pirated. Yes, I know it is virtually impossible, but if I could make it harder for hackers to crack my plugins, it would be fine. I made it work fine in python and in C++, but only in Xcode.
In Windows it is difficult. I only need to be able to access a username/password protected folder in my server and check if there is a file there. I don't even need to read the content of the file (but it would be nice to be able to do that too).
I started out using the cURL library but it is so complicated to make it work. I need 32 and 64 bit versions. Then I also have to include three .dll files in the folder of the application (that means that I would have to ask to the people who buy my plugins to copy three additional files to the main application folder... not a good thing )
So, any way to access a username/password protected folder on the net? (the username/password is generated in my code so, of course, I know what are the username/password to provide).
Also, I would need a way for the code to be completely self-contained, meaning that the users would not have to manually add any other files (libraries), besides the folder containing my plugin.
I am trying to pass a class as a type to a template class. This class's constructor needs an argument but I cannot find the correct syntax. Is it possible?
Here is an example of what I described above. I did not compiled it, it is for illustrative purpose only. And of course argument val of the myData constructor would be doing something more useful than simply initializing an int....
template <class T> class templateClass { templateClass() {};
[Code]....
My real code would only compile is I add the myData constructor:
myData () {};
and gdb confirmed that it is this constructor that get called, even with dummy(4).
I am working on a physics engine, following the cyclone physics engine source code but a I am having trouble with an error that is occurring in my overloaded operator== function. It is saying that the information is unaccessible.
I have `MainShop`(base class) then `SwordShop` and `BowShop`(derived classes) and another derived class called `Inventory`. I have a vector under protected in my base class, and when I access it from my derived classes it's okay, but each one has its own value. How can I set them all to have the same value?
//MainShop.h #pragma once class MainShop { private: //some variables protected: vector <string> WeaponInventory;
[code]......
Here every time I run it, it goes straight to the `else` and it displays that I do not have any items. I want to just have one vector for both my bow and Sword shops because vectors take up a lot of memory and my teacher said keep them to a minimum. So I just want one vector that takes in items from my bow class as well as my sword class, but for some reason it's acting as if I have multiple vectors, each with its own set of items.
I have two from in visual studio 2010 with C#. In form1 I have one combobox and one button .In form2 I have Reportviewer . When Button in form1 is clicked form2 is shown. Now my problem is when I click button to show form2 on the line Form2.Show(); this error appear : Attempted to read or write protected memory. This is often an indication that other memory is corrupt. What can i do? In form1 I have one combobox that combo fill with Database with this code in the Form Load:
I have CAN Dll program for my application,which was separately used.Now I have included the Drivers program into my application Program and I am having this error System Access Violation Exception:Attempted to read or write protected memory.i am attaching the Dll code and Application code which is throwing this error.
My Application Code which is the receiver thread for accessing the messages got onto the CAN bus.
DWORD WINAPI Rcv_Msg(LPVOID param){ int*MsgId = new int;//msg id from CAN intRcvVal;//0 = there is data in the queue; 1 = there is no data unsigned int uMsgId; *MsgId = 0; unsigned char CanData[8];