c++

std::binary_function - no match for call?

Hi, this is my code: #include <iostream> #include <functional> using namespace std; int main() { binary_function<double, double, double> operations[] = { plus<double>(), minus<double>(), multiplies<double>(), divides<double>() }; double a, b; int choice; cout << "Enter two numbers" << endl; cin >> a >> b; cout << "E...

Using a checked STL implementation, anything available for free?

Have you used a checked STL implementation? Did it find bugs you were not expecting? Is there one I can try on Linux for free? ...

Strongest cipher available to use with C/C++ ?

I am just wondering if you are supposed to write a sort of really secure application with data being transmitted over insecure networks, what kind of encryption algorithm will you use it in order to make it safe ? I know several c++ libraries for encryption providing nice functions with different algorithms, but i'm not quite sure which ...

Populate a vector with all multimap values with a given key

Given a multimap<A,B> M what's a neat way to create a vector<B> of all values in M with a specific key. e.g given a multimap how can I get a vector of all strings mapped to the value 123? An answer is easy, looping from lower->upper bound, but is there a neat loop-free method? ...

C++ STL vector iterator... but got runtime error

I'm studying STL and made win32 project.. But I got stuck in runtime error.. I tried to debug it but.. (partial code) vector<Vertex> currPoly=polygons.back(); vector<Vertex>::iterator it; for(it=currPoly.begin();it!=currPoly.end();++it){ vector<Vertex>::iterator p1; vector<Vertex>::iterator n1; vector<Vertex>::iterator ...

Linker error when compiling boost.asio example

Hi, I'm trying to learn a little bit C++ and Boost.Asio. I'm trying to compile the following code example: #include <iostream> #include <boost/array.hpp> #include <boost/asio.hpp> using boost::asio::ip::tcp; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: client <host>" << std::endl; ...

Is it a good idea to create an STL iterator which is noncopyable?

Most of the time, STL iterators are CopyConstructable, because several STL algorithms require this to improve performance, such as std::sort. However, I've been working on a pet project to wrap the FindXFile API (previously asked about), but the problem is it's impossible to implement a copyable iterator around this API. A find handle c...

The best cross platform (portable) arbitrary precision math library

Dear ninjas / hackers / wizards, keywords: bignum, bigint, GMP, MPFR, decNumber, BigInteger, BigDecimal, java.math.BigInteger, java.math.BigDecimal, System.Numerics.BigInteger I'm looking for a good arbitrary precision math library in C or C++. Could you please give me some advices / suggestions? The primary requirements: It MUST ha...

Linking with Boost error

I just downloaded and ran the boost installer for version 1.42 (from boostpro.com), and set up my project according to the getting started guide. However, when I build the program, I get this linker error: LINK : fatal error LNK1104: cannot open file 'libboost_program_options-vc90-mt-gd-1_42.lib' The build log adds this (I've replace...

Why can't I create a templated sublcass of System::Collections::Generic::IEnumerable<T>?

I want to create a generic IEnumerable implementation, to make it easier to wrap some native C++ classes. When I try to create the implementation using a template parameter as the parameter to IEnumerable, I get an error. Here's a simple version of what I came up with that demonstrates my problem: ref class A {}; template<class B> re...

Upper bound for custom rand48

Hi everyone, I'm using a custom random number function rand48 in CUDA. The function does not allow an upperbound to be set, but I require the output to be between 0 and 1. I guess I'm missing something but how would I convert the output to be between 0 and 1, the length of the number can change e.g. 697135872 would need to be divided ...

Two-phase lookup: can I avoid "code bloat"?

Two-phase lookup question: Is there a more synthetic way to write this code, i.e. avoiding all those using directives? Something like using CBase<T>; is what I would like, but it is not accepted. #include <iostream> template <typename T> class CBase { protected: int a, b, c, d; // many more... public: CBase() { a = 1...

What container type provides better (average) performance than std::map?

In the following example a std::map structure is filled with 26 values from A - Z (for key) and 0 - 26 for value. The time taken (on my system) to lookup the last entry (10000000 times) is roughly 250 ms for the vector, and 125 ms for the map. (I compiled using release mode, with O3 option turned on for g++ 4.4) But if for some odd reas...

Is there a way to increase the efficiency of shared_ptr by storing the reference count inside the controlled object?

Hello everyone :) This is becoming a common pattern in my code, for when I need to manage an object that needs to be noncopyable because either A. it is "heavy" or B. it is an operating system resource, such as a critical section: class Resource; class Implementation : public boost::noncopyable { friend class Resource; HANDLE ...

Problems with delete in destructor

Hello, I wrote this code. The constructor works normally, but in the destructor I get "Windows has triggered a breakpoint." How should I correct this? template class CyclicalArray { private: T* mem_ptr; public: CyclicalArray(size_t capacity, const T& default_value) { this->default_value = default_value; this->capacity = ...

Getting a job in the games industry as a developer, just knowing a game engine

I recently enrolled in a community college for games developement. But I am skeptical about the curriculum. I have no experience in the gaming industry so I wouldn't be able to tell whether it's a good investment or not. So I am asking you. I don't want to get too much into the details of all the classes I am taking so I will try to be ...

Undefined reference to ...

I keep getting this error message every time I try to compile, and I cannot find out what the problem is. any help would be greatly appreciated: C:\DOCUME~1\Patrick\LOCALS~1\Temp/ccL92mj9.o:main.cpp:(.txt+0x184): undefined reference to 'List::List()' C:\DOCUME~1\Patrick\LOCALS~1\Temp/ccL92mj9.o:main.cpp:(.txt+0x184): undefined referenc...

Segmentation Fault when trying to push a string to the back of a list.

I am trying to write a logger class for my C++ calculator, but I'm experiencing a problem while trying to push a string into a list. I have tried researching this issue and have found some information on this, but nothing that seems to help with my problem. I am using a rather basic C++ compiler, with little debugging utilities and I've...

How to create a const boost matrix?

How can I create a const boost matrix? The following did not work: const boost::numeric::ublas::matrix<double> arrayM(1, 3) = { {1.0, 2.0, 3.0} }; ...

Is there a practical benefit to casting a NULL pointer to an object and calling one of its member functions?

Ok, so I know that technically this is undefined behavior, but nonetheless, I've seen this more than once in production code. And please correct me if I'm wrong, but I've also heard that some people use this "feature" as a somewhat legitimate substitute for a lacking aspect of the current C++ standard, namely, the inability to obtain the...