c++

Prevent Duplicate Entry into HashTable C++

Hello, I was wondering if i could get some help to prevent a duplicate entry into my hashtable: bool hashmap::put(const stock& s, int& usedIndex, int& hashIndex, int& symbolHash) { hashIndex = this->hashStr( s.m_symbol ); // Get remainder, Insert at that index. symbolHash = (int&)s.m_symbol; usedIndex = hashIndex; while...

LNK2019 and LNK1120 with templated function

After having some problems with these two linker errors on SO, I have them again. However, this time the source seems to lie at another point. compiler error shows that it cannot find a function with signature ""public: unsigned int __thiscall MyClass::myFunction<unsigned int>(int)const ". However, moving the contents of myClass.cpp to...

What is the difference, usage-wise, between defines/macros/structs and consts/funcs/classes? (C++)

I know that the difference between defines and constants is that constants have type, and that between macros and functions, functions are called, and typed, whereas macros are untyped inline. Not so much the difference between structs and classes, but I don't think there is one, besides the public/private default thing (and I'm taking ...

How can I use a class with the same name from another namespace in my class?

I have two classes with the same name in different namespaces. I want one of these classes to reference the other class. The reason is that I am migrating to some newer code and I want to update the old code to simply pass through to the newer code. Here is a super basic example: namespace project { namespace legacy { class Content { ...

Is putting a function within an if statement efficient? (C++)

I've seen statements like this if(SomeBoolReturningFunc()) { //do some stuff //do some more stuff } and am wondering if putting a function in an if statement is efficient, or if there are cases when it would be better to leave them separate, like this bool AwesomeResult = SomeBoolReturningFunc(); if(AwesomeResult) { //do ...

Difference: std::runtime_error vs std::exception()

What is the difference between std::runtime_error and std::exception? What is the appropriate use for each? Why are they different in the first place? ...

C++ interview preparation

I have a Phone interview coming up next with with a company which works in financial software industry. The interview is mainly going to be in C++ and problem solving and logic. Please tell me the method of preparation for this interview. I have started skimming through Thinking in C++ and brushing up the concepts. Is there any other way...

Open Source C++ game engine math libraries?

I'm looking for a free to use game engine math library. Specifically I'd like a good matrix and vector implementation. And everything needed to move objects in 3D space. Does anyone know any good ones? I'm targeting OpenGL. I'd like to write them myself but don't have the time LOL. ...

hashkey collision when removing C++

Hello. To make the search foreach "symbol" i want to remove from my hashTable, i have chosen to generate the hashkey i inserted it at. However, the problem that Im seeing in my remove function is when I need to remove a symbol from where a collision was found it previously results in my while loop condition testing false where i do not w...

Rendering different triangle types and triangle fans using vertex buffer objects? (OpenGL)

Hello, About half of my meshes are using triangles, another half using triangle fans. I'd like to offload these into a vertex buffer object but I'm not quite sure how to do this. The triangle fans all have a different number of vertices... for example, one might have 5 and another 7. VBO's are fairly straight forward using plain tri...

Any good C++/C NNTP libs?

I came across some crusty and limited efforts awhile back but I was wondering if there was something truly functional that I missed, preferably in C++ but C is better than nothing. ...

Why does memcpy fail copying to a local array member of a simple object?

Classic memcpy gotcha with C arrays as function arguments. As pointed out below, I have an error in my code but the erroneous code worked in a local context! I just encountered this weird behaviour in a porting job, where I'm emulating the Macintosh Picture opcode playback using objects. My DrawString object was drawing garbage on playb...

Which STL Container?

I need a container (not necessarily a STL container) which let me do the following easily: Insertion and removal of elements at any position Accessing elements by their index Iterate over the elements in any order I used std::list, but it won't let me insert at any position (it does, but for that I'll have to iterate over all element...

How to capture ping's return value in C++

Hi! Does anyone know, how to capture ping's return value in c++? According to this link: ping should return 0 on success, 1 on failure such as unknown host, illegal packet size, etc. and 2 On a unreachable host or network. In C++ I called ping with the system (), e.g. int ret = system("ping 192.168.1.5");. My problem is, that ret's v...

C++ Linked List Memory Management

I'm attempting to craft my own basic singly linked list in C++ as a learning exercise, and I'm encountering some difficulty in the memory management department. As it stands I have... A 'Node' class: class Node { public: char *value; Node *next; Node(); ~Node(); }; Node::Node() { } Node::~Node() { delete[] value; ...

Why is my DLL failing to register?

I am building a project in VS2005 and several of my DLLs are failing to register. The error message I am getting in Visual Studio is: Project : error PRJ0019: A tool returned an error code from "Registering ActiveX Control..." which is nicely vague. When I register the DLL manually through the command line (using regsv32.exe, I g...

C++ inheritence for on-stack objects

I have a base class, Token. It has no implementation and as such acts as a marker interface. This is the type that will be used by callers. { Token t = startJob(jobId); // ... (tasks) // t falls out of scope, destructors are called } I have a derived class, LockToken. It wraps around a mutex and insures the lock is acquire...

Warning linking boost lib in WDK build ("LNK4217: locally defined symbol _ imported in function _")

I'm building the below example boost-consuming user-mode app with the WDK, but I'm getting the following errors when linking with the boost libraries that I built earlier using bootstrap and .\bjam, from the same terminal window. IIUC, MSDN says it's because the (hideously mangled) function - which appears to be a C++ std lib function -...

Visual C++ compiling error

When compiling these two files I am getting numerous errors. Please help me out. stchart.cpp # include "peg.hpp" # include "stchart.hpp" # include "stchart_res.hpp" external PegResourceTable stchart_ResourceTable; PEGINT gChartData [] = (100, 100, 100, 100, 100, 100, 125, 150, 175, 200, 150, 100, 50, 100...

How should application perform in 64-bit vs. 32-bit intel architectures?

I want to know the relative performances of a normal C++ application in the following scenarios: Built as 32-bit app, run on Intel 64-bit processor (x64-64) Built as 32-bit app, run on Intel 32-bit processor (x86) Built as 64-bit app. Also, what factors should I consider when modifying / developing the application to make it to run f...