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1
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0answers
56 views

Managing reference-like members with shared pointers [on hold]

It is a well-known fact that there is no built-in mechanism that prevents member fields that are references from being invalidated, even if they are const. (For more background see: ...
4
votes
0answers
67 views

possible to achieve Rust's ownership model with a generic C++ wrapper?

Looking through this article on Rust's concurrency safety: http://blog.rust-lang.org/2015/04/10/Fearless-Concurrency.html I was wondering how many of these ideas can be achieved in C++11 (or ...
2
votes
2answers
129 views

How to write unit tests for network client?

I need to write simple http client. It could be great to have unit tests for my class. But I don't know how to write proper and testable class. For example, I have a client like this: class ...
3
votes
1answer
136 views

Unique pointer initialisation

What is the correct initialisation of a smart pointer? std::unique_ptr<Class> ptr(std::make_unique<Class>()); or std::unique_ptr<Class> ptr = std::make_unique<Class>(); ...
1
vote
1answer
127 views

Async I/O operations - proper way to avoid deleting object

Using async I/O operations from boost::asio I often need shared pointers (and enable_shared_from_this and shared_from_this in callbacks) to avoid deleting objects too early. I think that it could be ...
4
votes
2answers
307 views

Designing an in-memory table in C++

I'm evaluating my options to structure an in-memory database and I have a few ideas of how to implement it. I would like to know your opinion of what the best design choice is. I have a column class ...
0
votes
1answer
72 views

Blocking queue for token based synchronization

I'm currently looking for a good solution for the following use-case in C++ (preferably C++11 or C++14): The program is running a server with a TCP connection. Other clients can connect at any time ...
10
votes
1answer
765 views

Object lifetime invariants vs. move semantics

When I learned C++ long ago, it was strongly emphasized to me that part of the point of C++ is that just like loops have "loop-invariants", classes also have invariants associated to the lifetime of ...
7
votes
2answers
311 views

Compile-time checking for NULL initialized std::string

This is sort of the complementary question to How to best protect from 0 passed to std::string parameters?. Basically, I'm trying to figure out whether there is a way to have the compiler warn me if a ...
4
votes
1answer
130 views

Which C++ IO interfaces for a complex data source i.e. converter

My question: When you've got a complex converter like, that takes chunks or large result sets out of a database, converts it into a line by line file/resource in the end, should one either design it ...
1
vote
2answers
238 views

Preferable design of scope guard in C++

Recently, I come across an issue about the design of scope guard. A scope guard invokes a supplied function object (usually performs cleanup procedures) upon exiting the enclosing scope. The current ...
2
votes
2answers
221 views

Does it make sense to have a user specified thread limit?

I'm developing a C++14 application and would like to take advantage of the new multithreading features, in particular std::async. I have seen a number of applications which allow the user to specify ...
0
votes
1answer
69 views

Containers and shared ownership within a class instance

I have two objects as member variables of a class. std::unique_ptr<Object> specificObject; std::vector<std::unique_ptr<Object>> objects; I know that specificObject will always be ...
1
vote
2answers
234 views

Should I use a jump table or a switch case statement for similar functions but may have some parameters that are not relevant [closed]

I had a HUGE switch/case statement, which I converted to use a function dispatch table using an enum list for the index. My colleague (who is doing a code review on this change) agreed that it should ...
5
votes
2answers
245 views

How to optimize/parallelize the following clustering/joining algorithm:

I have relatively-small algorithm that takes up ~60% of the total run-time of my scientific code (57 lines of 3600), so I would like to find a way to optimize what I'm doing and make the code ...
0
votes
1answer
224 views

Where is the dynamic memory associated with std::bind?

The problem is that since you can use std:bind in a loop with an arbitrary number of iterations, the storage cannot be inline. It doesn't appear to be on the heap, since it doesn't appear to generate ...
4
votes
3answers
285 views

C++ returning persistent objects

I'm currently trying to learn best practices in C++ after coming from a C# background. I understand that there are three ways of handling objects: By value (objects are copied or moved when passed ...
4
votes
3answers
313 views

What are R-value references used for?

I'm trying to dig deep into C++ and really learn the nuances of the language but one thing I've found to be really confusing is the R-Value reference. The whole double ampersand thing to be clear (in ...
133
votes
11answers
20k views

Should I stop using the term C/C++?

I understand C and C++ are different languages but when I was learning C++ I was always told that C is a subset of C++ or C++ is C with classes. And that was quite true until the appearance of C++x0, ...
1
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0answers
131 views

Switching from Node.js class techniques to C++

I'm going to be rewriting a project from Node.js into C++11. The device the Node.js scripts are being run on are ARM based, and Node.js is slow to start up on the device. In the Node.js program, I ...
4
votes
1answer
140 views

Refactoring numerical code for TDD and encapsulation

I am coming to terms with TDD, and the fact that I need to re-factor some code that I'm (re)writing. I am having a problem that I think is a classic conflict---TDD vs. encapsulation of private ...
8
votes
1answer
528 views

C++ serialization design review

I am writing a C++ application. Most applications read and write data citation needed and this one is no exception. I created a high level design for the data model and serialization logic. This ...
5
votes
1answer
113 views

C++11 Lambda vs Helper Member Functions

There are a bunch of methods in a class that I want to clean up. These just build up a data structure (with different values) over and over again and add them to a container passed in, like so: ...
7
votes
1answer
490 views

Key / Value store development porting to modern C++

I am developing a database server similar to Cassandra. Development were started in C, but things became very complicated without classes. Currently I ported everything in C++11, but I am still ...
5
votes
5answers
326 views

Can a pimpl variation be implemented without any performance penalty?

One of the issues of pimpl is the performance penalty of using it (additional memory allocation, non-contiguous data members, additional indirections, etc..). I would like to propose a variation on ...
5
votes
1answer
224 views

Strategy for OS X and downlevel version of C++11 library?

I think I've found myself in a situation where things are quickly spiraling out of control, and I'd like to get some feedback to select a way to proceed. BACKGROUND I'm working with a library based ...
1
vote
1answer
254 views

How to handle design changes for auto_ptr deprecation in C++11?

We are testing a library under C++11 (i.e., -std=c++11). The library uses auto_ptr and this pattern: Foo* GetFoo() { autoptr<Foo> ptr(new Foo); // Initialize Foo ...
0
votes
0answers
85 views

C++ object design

I am programming a database similar to Cassandra. I use C++. Simplified database store its data in one or two "memory table" and several "disk tables", all stored in single directory. I have class ...
2
votes
1answer
346 views

Expandable alternative to Visitor pattern for tree traversal?

I have a tree containing various subtypes of the my base node class. I now want to traverse this tree and do something with the nodes depending on their type. The most straightforward idea is to just ...
2
votes
2answers
240 views

Member and Function Injection in C++ Across Multiple Classes

I have a problem in which a variety of classes in C++ will want some functionality that is neither a "has a" nor an "is a" relationship. The problem is that there are some members with associated ...
1
vote
0answers
249 views

Best software architecture for an efficient network tunneling in C++

Before jumping to my questions, let me explain my project's background. I am part of a team that organize the network of a famous LAN event. Most of the games nowadays actually don't run locally but ...
0
votes
1answer
681 views

pthread versus boost::thread - need to set the thread priority on an ubuntu box

I wrote a class that basically executes a numerical analysis code in a thread using boost::thread. Now I need to specify the thread priority, since we are running a system with near real-time ...
1
vote
1answer
730 views

Is returning a reference to inside a private vector bad practice?

I have the following trimmed class: #include <vector> #include "Tile.h" class Board { std::vector<Tile> boardArr; // VVV Bad Practice? Safe? Tile& getTileAt(unsigned ...
3
votes
1answer
543 views

Are there real world examples demonstrating reasonable performance improvement by using move semantics?

(I've asked a similar question on SO but unfortunately it might not be proper, so I also put here; please kindly point out if you think it's a duplicate.) I've heard many words about the move ...
0
votes
1answer
228 views

Moving from C++ to NodeJS - Working with XML and JSON

I need to make a program to compare several large +100MB XML files, find the difference, and spit out JSON. I have written the comparison code in C++ and it performs great but now when I am getting to ...
1
vote
1answer
96 views

Run a c++ program under lots of different data maps

I want to run a c++ program to process a lot of data from different xml files and output results. I run the program once per file and potentially have around 50 different files. The trouble is each ...
1
vote
1answer
102 views

Calculating the determinant of a matrix

I am working on a library (in my spare time) that I hope to open source soon. One of the elements in the library is a method for calculating the determinant of a given input matrix. For this, I have ...
0
votes
1answer
282 views

Best algorithm for “ACM ICPC Team”

I have this problem (complete description): There is a list of persons N and M topics. I have to find out the maximum number of topics a 2-person team can know. And also find out how many teams can ...
1
vote
1answer
209 views

Avoiding std::forward and Rvalue References

I recently read the Google C++ Style Guide and especially one part catched my eye. The part about Rvalue References discourages from using std::forward in general and using rvalue references in other ...
4
votes
3answers
2k views

Const means Thread-safe? [closed]

I was put onto this video: http://channel9.msdn.com/posts/C-and-Beyond-2012-Herb-Sutter-You-dont-know-blank-and-blank By http://codereview.stackexchange.com/users/39810/glampert Because I asked ...
2
votes
2answers
200 views

c++11 random: why different range of int and real?

In the c++11, we now have <random> to produce random number. About uniform distributions, we have following int_distribution and double_distribution: uniform_int_distribution-produces integer ...
3
votes
3answers
466 views

Polymorphic template container: shared_ptr vs reference_wrapper

Assuming we have two classes: class A { ... } class B : public A { ... } Would it be better to write std::deque<shared_ptr<A> > container; or ...
1
vote
2answers
243 views

operator“” in modern C++

I took an example I found on-line whereby a constexpr of the form _binary could be evaluated at compile time as an unsigned long long and then I tried to generalize it for any base from 2 to 36. For ...
3
votes
1answer
198 views

When to use nested classes and when to use namespaces?

I have really never made use of namespaces, and am considering them at the moment. My situation. I have a class Reverb. It contains as members instances of other classes, declared in the same header ...
0
votes
2answers
221 views

Is it bad form to break out of Range-based for

I have a range-based for that operates over a std::vector of objects (items), like so: for(auto item : itemCollection) { if(!item.some_check(...)) { // do 5% stuff break; } ...
13
votes
2answers
2k views

Is this a good pattern: replacing a long function with a series of lambdas?

I recently run into the following situation. class A{ public: void calculate(T inputs); } Firstly, A represents an object in the physical world, which is a strong argument for not splitting the ...
9
votes
3answers
244 views

Will destructing a large list overflow my stack?

Consider the following singly linked list implementation: struct node { std::unique_ptr<node> next; ComplicatedDestructorClass data; } Now, suppose I stop using some ...
2
votes
1answer
348 views

Should a lockfree queue use a condition variable?

Suppose I have a lockfree queue in a multithreaded setting. I already provide a try_dequeue() method which allows for an optional failure (communicated via the return type) if the queue is empty. ...
3
votes
2answers
202 views

How to deal with historic exception specifications in maintained C++ code

Today, I discovered a few exception specifications in legacy code I've to maintain, when Cppcheck 1.68 ([Inconclusive] but correctly) pointed out that the specified exceptions are not handled in ...
2
votes
1answer
221 views

How to make max-heap stable with counter and account for counter overflow?

Generally I need size-efficient data structure similar to std::priority_queue but stable (preserving order of insertion). By adding just 4 bytes to the object I could have 1 byte serving as priority ...