October 25, Pavia, Italy
November 6-8, Berlin, Germany
November 3-8, Kona, HI, USA
By Adrien Hamelin | Oct 20, 2016 12:13 PM | Tags: intermediate
Friends are nice, but not in C++.
Passkey Idiom: More Useful Empty Classes
by Arne Mertz
From the article:
After last week’s post about tag dispatch let’s have a look at another example for useful empty classes: The passkey idiom can help us regain control that we would give up by simply making classes friends.
By Vittorio Romeo | Oct 19, 2016 05:11 AM | Tags: c++17
The article covers a technique that allows variant types (both `std::variant` and `boost::variant`) to be visited using lambdas, without having to explicitly create a functor.
visiting variants using lambdas - part 1
By Vittorio Romeo
From the article:
Visiting a variant is usually done by writing a visitor struct/class outside of the scope where the variant is actually being visited. [...] It is possible to build such an object locally in the call site [...] by implementing something similar to `std::overload`.
By Adrien Hamelin | Oct 18, 2016 01:42 PM | Tags: basics
The “unsigned” Conundrum
by Tony “Bulldozer00” DaSilva
From the article:
A few weeks ago, CppCon16 conference organizer Jon Kalb gave a great little lightning talk titled “unsigned: A Guideline For Better Code“. Right up front, he asked the audience what they thought this code would print out to the standard console:
Even though -1 is obviously less 1, the program prints out “a is not less than b“. WTF?
By Adrien Hamelin | Oct 14, 2016 02:32 PM | Tags: community
ACCU’s Overload journal of October 2016 is out. It contains the following C++ related articles.
Overload 135 is now available
From the journal:
Determinism: Requirements vs Features
A program can easily be non-deterministic. Sergey Ignatchenko considers how to define determinism. by Sergey Ignatchenko
Eight Rooty Pieces
Finding a square root is a common interview question. Patrick Martin demonstrates eight different ways to find a root. by Patrick Martin
Polymorphic Comparisons
Polymorphic comparisons require much boilerplate. Robert Mill and Jonathan Coe introduce a template utility for such comparisons. by Robert Mill and Jonathan Coe
C++ Synchronous Continuation Passing Style
Direct and continuation passing styles differ. Nick Weatherhead explains a continuation passing style for synchronous data flow. by Nick Weatherhead
Attacking Licensing Problems with C++
Software licenses are often crackable. Deák Ferenc presents a technique for tackling this problem. by Deák Ferenc
By Vittorio Romeo | Oct 12, 2016 02:29 AM | Tags: None
Article covering "camomilla", a Python script designed to post-process heavily-template-based C++ errors in order to make them easier to read.
camomilla: C++ error simplification script
by Vittorio Romeo
From the article:
camomilla uses simple text transformations to make gcc and clang errors smaller and easier to read. [...] The main text transformation used by camomilla to prevent full expansion of templates is "template typename collapsing", which hides nested typenames up to a user-specified depth. [...] The two other current transformations offered by camomilla are simple regex replacements that can act on namespaces or generic symbols. They can be defined in .json configuration files (which can recursively include each other!) [...] camomilla helps with [continuously transforming the same error] by automatically caching the last processed original error, so that the user can play around with different transformations and options.
By Meeting C++ | Oct 11, 2016 05:57 AM | Tags: intermediate efficiency deep learning cuda basics advanced
Today a new version of DLib is available:
DLib 19.2 released
Release notes
by Davis King
From the article:
... So the obvious thing to do was to add an implementation of MMOD with the HOG feature extraction replaced with a convolutional neural network. The new version of dlib, v19.2, contains just such a thing. On this page you can see a short tutorial showing how to train a convolutional neural network using the MMOD loss function. It uses dlib's new deep learning API to train the detector end-to-end on the very same 4 image dataset used in the HOG version of the example program. Happily, and very much to the surprise of myself and my colleagues, it learns a working face detector from this tiny dataset.
By Marco Arena | Oct 11, 2016 12:46 AM | Tags: intermediate
Marco Foco shows different solutions and tradeoffs to a dangling reference problem:
Optimizing return values
by Marco Foco
From the article:
As you can see, class C contains a function
get()which returns a reference to its internal state. In normal code, we must take care not to use this reference after our class has been destroyed...
By Adrien Hamelin | Oct 10, 2016 12:22 PM | Tags: c++11 basics
Quick A: Yes.
Recently on SO:
Is the 'override' keyword just a check for a overriden virtual method?
That's indeed the idea. The point is that you are explicit about what you mean, so that an otherwise silent error can be diagnosed:
struct Base { virtual int foo() const; }; struct Derived : Base { virtual int foo() // whoops! { // ... } };The above code compiles, but is not what you may have meant (note the missing
const). If you said instead,virtual int foo() override, then you would get a compiler error that your function is not in fact overriding anything.
By Vittorio Romeo | Oct 8, 2016 10:56 AM | Tags: None
Brief trip report covering thoughts and "lessons learned" from the author's favorite talks and his own sessions.
trip report - CppCon 2016
By Vittorio Romeo
From the article:
CppCon 2016 ended yesterday - I had the pleasure of attending and presenting at this amazing conference again this year.
I'm really grateful to Jon Kalb, Bryce Lelbach, the conference staff, the speakers, my company and everyone else involved for making this possible.
In the same vein as my C++Now 2016 trip report, I wanted to share my thoughts regarding the talks I liked the most and regarding my sessions.
By Vittorio Romeo | Oct 8, 2016 10:54 AM | Tags: None
Analysis of a library development technique that allows users to decide whether or not to consume the library as "header-only".
opt-in header-only libraries
by Vittorio Romeo
From the article:
Libraries can be designed and implemented in order to allow users to choose between header-only usage, static linking or dynamic linking. [...] The main idea is to conditionally include .cpp files depending on a preprocessor macro, which can be defined during compilation. Functions also have to be conditionally decorated with the inline specifier.
