I'm trying to write a custom allocator that I can use with the STL. Here's what I have so far :
Code:
#include <cstddef>
#include <iostream>
#include <memory>
#include <vector>
template<class T>
struct customallocator {
[Code].....
I'm doing and currently, my push_back doesn't seem to do anything.
I attempted to create a dynamic array class for use in my engine (due to problems regarding a dll-interface with the standard library), so I tried at making a standard-compatible allocator template class first. After I "finished" that, I went on to work on the dynamic array class itself.So I finish the dynamic array class, and test it with the standard allocator. It works perfectly, but when I test it with my custom allocator class, it fails terribly.
To make sure it wasn't my DynamicArray class that was causing issues, I tried using the custom allocator on the std::vector class template, and it didn't work either. IMy DynamicArray class code:
// Represents a dynamic array, similar to the standard library's "vector" class.
template<typename T, typename A>
class DynamicArray
{
public:
DynamicArray() :
data(nullptr),
elements(0),
capacity(0)
[code].....
The "Request" and "Free" functions are my engine's equivalent of malloc and free (or new and delete). I allocate a large buffer (16 mb), and through those functions I distribute the memory to where it's needed.
Does the requirements have changed for writing custom allocators with C++ 0x11?
A custom allocator (that uses a fixed array as its memory pool) that I have been using successfully for some time, now throws an exception!
It runs fine under VS2008 but bombs out with VS2010.
I have a class like this:
#include <string>
using namespace std;
//-----------------------------------------------
class Prenumeratorius {
private:
string pavarde;
string adresas;
string leidinioKodas;
[code]....
bunch of variables, constructor, setter and getter.And I have this class:
#include <vector>
class Leidinys {
private:
string kodas;
string pavadinimas;
double vienetoKaina;
[code]....
in to my "Leidinys.h" header file, I get a build error, I tried to remove same includes in both files, that didn't worked.
I have a matrix class who use the stl vector to manage its
memory(UInt is typedef of size_t):
class Mtrx {
protected:
[Code]....
However, the two different classes are only different with each other on the allocator. I am thinking, that a elegant way should be merging them together.
To my understanding, a Container should have an Allocator member data, which is used internally.
Question: what happens, for example, when we swap() two containers that use different allocators?
Must the allocators be swapped as well?
Must all elements of the container be reallocated when the allocator is changed?
Consider a singly-linked list container.
Being constructed with an alloc<T>, it will rebind it as alloc<node<T>> for internal use.
Question: is allocator_type the same as alloc<T> or as alloc<node<T>>?
I am coding a singly-linked list container. Of course, internally it uses Node<T>.
Question: what is the correct way to use the allocator given by the user? I ask, because I've read this on the rival C++ Reference:
std::list<T, A> allocates nodes of some internal type Node<T>, using the allocator std::allocator_traits<A>::rebind_alloc<Node<T>>, which is implemented in terms of A::rebind<Node<T>>::other if A is an std::allocator
[URL]...
The above doesn't seem right to do, because then what should pointer and const_pointer be?
using pointer = std::allocator_traits<Alloc>::pointer;
using const_pointer = std::allocator_traits<Alloc>::const_pointer;
// but we're using Alloc<Node<T>> not Alloc<T>
// so maybe do this?
using pointer = value_type *;
using const_pointer = const value_type *;
How to build the static library on my own using visual C++ 2008.
I used the following code to create the header file and cpp of the library.but I am unable to compile due to the following error.
// MathFuncsLib.h
namespace MathFuncs {
class MyMathFuncs {
public:
// Returns a + b
static double Add(double a, double b);
[Code] .....
Error I get while it is compiled :
Error3error C2653: 'MyMathFuncs' : is not a class or namespace name
class test {
private:
string name="";
public:
event void changedname();
void setname(string value)
[code]....
i get error about 'a' and 'b' not be a class. but using a template can i validate these code?
my problem is that i don't know how to use objects outside of functions / these is polymorphism, but not accepted by C++
I need to build an array in a function and return that array. Well, two arrays actually, which means I can't return it in the return statement.
Long term, this function/method is supposed to return two populated buffers for further processing. The buffers/arrays are loaded from a file. So, the size of the array is completely unknown until after the file is read. So, you can't have a fixed size array until the function is almost ready to return.
I'm hardcoding the arrays here for testing purposes, but eventually they will be loaded in from a file. That's the whole purpose of this.
Anyway, I need to pass the arrays that are created in this function/method to the caller. But I can't figure out how to do it. The code "almost" works, except that it's overwriting my array when it returns.
Here's the method:
bool GameModelClass::LoadBuffersFromPUNCFile(std::wstring PUNCFileName, VERTEX* &VertexListPointer, unsigned int* &IndexListPointer) {
VERTEX GroundVertexList[4] = {
[Code]....
VertexListPointer returns the correct data structure (actually its an array of structures). The problem is that the first time I use the other variables it over rights the array. The pointer still points to the same spot, but VertexBufferDescription is next to the VertexListPointer and so completely overwrites it.
What I "think" I want is to allocate the array in a totally different area of memory. VertexListPointer should be a pointer, not a contiguous block of memory. It should point to the contiguous block of memory elsewhere.
This is where my weak understanding of pointers comes back to bite me in the posterior end.
In the end, I just want to pass back two arrays/buffers to be used by the calling code.
I am not sure how to build the tree with values:
Code:
struct Node *root = 1 root->left = 2
root->right = 3
root->left->left = 4;
root->left->right = 5;
Everything should be right except the main(). How to demonstrate this program correctly?
Code:
#include <iostream>
#include<stdio.h>
#include<stdlib.h>
#include <stack> // std::stack
[Code] .....
10,11,20,1512,22,24,19,22
i want to write a c++ program to build min heap which gets above values from user. remember this program should not alloduplicate values to enter. it should discard duplicate values.
i have four email adresses (for various reasons) and i could probably find a client for all three on source forge, but i thought it would be good practice to use my own. i want to use boost, sdl, and c++, but i cant find a tutorial.
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Build a class named "salesCompany". Save it's name with a string and an array with records which will be filled with values from sales in different cities of the company.
Build the constructor which must get as a parameter the name of the company and a text file which will fill the array. There is an example of the text file format. Every line saves the sold quantity of a product, identified by a code, in a certain city.
CodeCityQuantity
1a63bCity11200
45ab8City2550
#include <iostream>
#include <string.h>
using namespace std;
class salesCompany {
[code].....
what should I add more and how can make it available for the user to enter as an input a text file.
I want to build a dll library with visual c++ 8.0 and got an "unresolved symbol" linker error message when trying to use the library with an application. So I checked the dll library with dependency walker for the exported functions, the needed functions were missing in the library.
I then dumped the corresponding object file with dumpbin.exe, the function was declared as public, like the other exported functions. On the next step, I set the verbose switch for link.exe.
The verbose log told me, that the function was discarded on the linker run. What can lead to that behaviour of the visual c++ linker ?
I'm trying to build a Linux Process Scheduler from scratch but dont know where to start.
View 1 Replies View RelatedI am trying to build a web application that uses p/invoke to access a method. Similiar to the one used here - [URL] However I keep getting the following error message - Unable to load DLL 'MyDll.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E) I read say to change the output directory to match that of the Mydll directory I have tried that and it still does not work.
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View 1 Replies View RelatedI have a set of projects. Each one builds either a static library or an executable. What I'd like to do, is at build time I want to embed a version string representing the version of the executable as well as the version of each library. These version strings will come from an external source (in my case it's based on a "git describe" call, but that's beside the point). Embedding such strings can be highly valuable for traceability. (Versions of 3rd-party libraries are not necessary.)
I'm using qmake as my build system, but this should work more or less similarly with any build tool. What I'd ideally like to do is define this process in such a self-contained way that a an absolutely minimal amount of additional code is required in order to leverage it. Preferably, nothing more than an include(version.pri) in each project's .pro file in order to collect the versions. (Retrieving them later, such as to respond to a --version command-line flag, can be done via traditional C++ methods.)
What I've done so far is to define a singleton VersionTracker class, and then tweak the build system so that "MODULE" and "VERSION" are preprocessor symbols defined at build time. I've also tweaked the build system so that a file in each project, version.cpp, is rebuilt (and regenerated if necessary) on every build regardless of changes. This source file can capture the information in the preprocessor symbols into each static library and the executable.
Now, here's the problem. How can I get the information from those version.cpp files into the VersionTracker class? I thought I could use a global object's constructor to do it, but it turns out the symbols are stripped out when the static libraries are linked so I only get the executable's version. I also found a page on stackoverflow detailing a very clever way to call a registration function at class definition time, but again the class definition appears to be stripped out if it's defined in the version.cpp file of a static library and not referenced elsewhere.
Everything I've read basically says you either need to use linker flags to prevent symbol stripping entirely, which is probably an adoption-killer for this hack, or you need to use an explicit registration function called from the executable. I'd prefer to avoid this since it is just another thing a programmer could forget to update when a library dependency is added or removed.
My last idea, which I haven't tried yet, would be to put each version.cpp into a separate static library from the one it is describing. This version-only library could be linked without symbol stripping. I don't love this concept but it might work.
I haven't yet figured out how shared libraries can be worked into this framework at all. I'll worry about that after I get static libraries working.
It compiles fine but hangs during linking. The last message I got is
Code generation.
Sometime when I cancel it, I got
LNK1257 code generation failed
What can be possible reasons and how to diagnose?
I'm supposed to build a banking simulation program around the BankAcct class, which provides the following service: create new account with unique account number (maximum 5 accounts created in a single test running); deposit/withdraw; print information of all existing account. I was running a test program with only 2 services first, namely creating new account and depositing, but the program just keep on crashing and I couldn't figure out why.
#include <iostream>
#include <sstream>
#include <string>
using namespace std;
[Code].....
I am getting some weird errors while building in release mode. It works fine in debug mode. Libraries and includes are linked in both debug and release version, but it's acting like it's not.
main.cpp
#define GLEW_STATIC
#include <glew.h>
[Code].....
I'm trying to build an array of a certain size, after receiving user input. The method I'm trying is
int var = 3;
int* ar = new int[var];
When doing tests I did this (and it worked) and red flags popped off in my head.
int var = 3;
int* ar = new int[var];
ar[0] = 0;
ar[1] = 1;
ar[2] = 2;
ar[3] = 3;
ar[4] = 4;
cout << ar[0] << ar[1] << ar[2] << ar[3] << ar[4] << endl;
This method is considered safe, and possibly tell me why I'm not getting stack errors when trying to overload the array?