October 25, Pavia, Italy
November 6-8, Berlin, Germany
November 3-8, Kona, HI, USA
By Guy | Sep 8, 2019 11:46 PM | Tags: None
Do you know the difference between replacing and overloading?
“Searching for another overload”: overloading and replacing new and delete with MSVC v142
by Guy Davidson
From the article
There are rather a lot of operator new functions; the standard defines 22, 14 of which are non-member functions. How does the new operator know which operator new to call?
By Adrien Hamelin | Sep 6, 2019 11:04 AM | Tags: community
We’re in the final countdown to this year’s CppCon, which starts on September 16. To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2019!
Modern C++ Design (part 1 of 2)
Modern C++ Design (part 2 of 2)
by Titus Winters
Summary of the talk:
The old rules for C++API design are due for an update - we have made ad hoc changes to design principles in the standard library, but haven’t really written down the new ideas. Parameter passing and API design for free functions/member functions is due for a general update, particularly as a result of rvalue-references and reference qualification. How do we pass non-owning references? How do we sink a T? How do we express “maybe move” APIs? When do we want reference-qualified overload sets? What does an rvalue-reference qualified non-overloaded method mean? How do we express call once semantics?
For types, our consistency in producing Regular types has weakened in recent C++ releases with types like unique_ptr (move-only) and string_view (reference semantics). These classes of design that have shown themselves to be valuable, but certainly surprising at first. As we should not continue to extend the set of type designs arbitrarily, this is a good time to look at type design in the modern C++ era and narrow down the set of designs that are generally favored. This talk will focus on modern C++ design from small (choice of passing by value or reference) to large (Regular types, reference types, move-only types, etc). We will also introduce a taxonomy of type properties as a means to discuss known-good type design families.
We will also dive into the discussion of whether Regular design covers all good design, or whether there is more to the story.
By Adrien Hamelin | Sep 6, 2019 11:00 AM | Tags: c++11 basics
Quick A: it is not possible
Recently on SO:
Removing item from vector, while in C++11 range 'for' loop?
No, you can't. Range-based for is for when you need to access each element of a container once.
You should use the normal for loop or one of its cousins if you need to modify the container as you go along, access an element more than once, or otherwise iterate in a non-linear fashion through the container.
For example:
auto i = std::begin(inv); while (i != std::end(inv)) { // Do some stuff if (blah) i = inv.erase(i); else ++i; }
By Adrien Hamelin | Sep 5, 2019 11:46 AM | Tags: community
We’re in the final countdown to this year’s CppCon, which starts on September 16. To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2019!
Spectre: Secrets, Side-Channels, Sandboxes, and Security
by Chandler Carruth
Summary of the talk:
The discovery of speculative execution side-channel attacks (called "Spectre") fundamentally changes the security model of every modern superscalar microprocessor. Extracting secret data (credit cards, cryptographic keys) through side-channels is not new and has challenged the cryptographic community for decades. Despite this, the industry has often been complacent in our response, viewing these attacks as impacting a tiny amount of code and being nearly impossible to weaponize. But speculative execution attack techniques have fundamentally altered the ease and applicability of side-channels, making them a serious threat to computer security. Responding to these issues has impacted CPU design, compiler design, library design, sandbox techniques and even the C++ programming language and standard.
This talk will explain how these kinds of attacks work at a high level and provide a clear set of terminology to describe these classes of vulnerabilities and attacks. It will show how the different variants work at the low level of modern hardware to give a detailed and precise understanding of the mechanics involved on CPUs today.
It will also provide guidance about what makes applications and services vulnerable and how to analyze your software to understand the degree of its exposure. It will include an overview of the numerous different mitigation techniques available, how to deploy them, and what tradeoffs come with them. Some of these mitigations will be covered in detail: how they work at a hardware level, where they don't work, and what attack vectors remain.
Finally, the talk will show how traditional side-channel risks are made substantially easier to exploit due to speculative execution. This will cover how cryptographic and other libraries dealing in high-value secrets need to be adapted to correctly defend against these attacks. Further, it will introduce general problems of sandboxing untrusted code from secret data and the current best techniques in those circumstances.
This talk will be accessible to most C and C++ programmers. No deep background on CPUs, assembly, hardware instructions, Spectre, side-channels, or security is needed.
By Adrien Hamelin | Sep 5, 2019 11:41 AM | Tags: basics
Quick A: default constructors are called if available, otherwise there is no initialisation.
Recently on SO:
How do C++ class members get initialized if I don't do it explicitly?
In lieu of explicit initialization, initialization of members in classes works identically to initialization of local variables in functions.
For objects, their default constructor is called. For example, for std::string, the default constructor sets it to an empty string. If the object's class does not have a default constructor, it will be a compile error if you do not explicitly initialize it.
For primitive types (pointers, ints, etc), they are not initialized -- they contain whatever arbitrary junk happened to be at that memory location previously.
For references (e.g. std::string&), it is illegal not to initialize them, and your compiler will complain and refuse to compile such code. References must always be initialized.
So, in your specific case, if they are not explicitly initialized:
int *ptr; // Contains junk string name; // Empty string string *pname; // Contains junk string &rname; // Compile error const string &crname; // Compile error int age; // Contains junk
By Adrien Hamelin | Sep 5, 2019 11:38 AM | Tags: community
Next presenter.
Presenter Interviews: Klaus Iglberger
by Bob Steagall
From the article:
In this week’s interview, Kevin chats with Klaus Iglberger about his upcoming class Modern C++ Design Patterns; we also find out more about the Back to Basics track and his talk on Move Semantics.
By Vittorio Romeo | Sep 3, 2019 11:25 AM | Tags: None
This article proposes a mechanism to allow seemingly backwards-incompatible changes to C++'s syntax while actually maintaining backwards compatibility, leveraging the isolation of upcoming module units. The idea is similar to Rust's "Editions" mechanism. The post explains how the feature would work and how C++ would benefit from it.
fixing c++ with epochs
by Vittorio Romeo
From the article:
Imagine that you have been designing a programming language for over 30 years and that it gradually became widely used across the globe. Some of the decisions you made at the beginning were excellent and contributed to the success of your project. Some others, however, were not the best: over the years you and your users realized that the world would have been a better place if those choices you made eons ago were slightly different. [...]
What if I told you that I could fix all of your problems? Even better, what if I told you that backward-compatibility will never be broken and that migration to newer versions of your language could be automated?
By Adrien Hamelin | Sep 2, 2019 11:21 AM | Tags: community
We’re in the final countdown to this year’s CppCon, which starts on September 16. To whet your appetite for this year’s conference, here’s another of the top-rated talks from last year. Enjoy – and register today for CppCon 2019!
Applied Best Practices
by Jason Turner
Summary of the talk:
What happens when we start a project from scratch and try to apply all of the best practices? How well do constexpr, noexcept, [[nodiscard]] and other features interact with each other? Is it possible to apply all of the best practices at once, or will they conflict with each other? We will explore current best practices and examine their impact on compile time, runtime and testing. We'll also see some of the unexpected effects that result when best practices are applied to a new project.
By Adrien Hamelin | Sep 2, 2019 11:12 AM | Tags: community
Last few myths.
More Myths of My Blog Readers
by Rainer Grimm
From the article:
Today, I conclude my story to your myths about C++. These myths are around function parameters, the initialisation of class members, and pointer versus references...
By egraether | Aug 31, 2019 12:19 PM | Tags: None
Sourcetrail is a cross-platform Visual Source Explorer based on LLVM/Clang
<img alt="" data-cke-saved-src="https://www.sourcetrail.com/blog/images/release_2019_3/composition_trail.png" src="https://www.sourcetrail.com/blog/images/release_2019_3/composition_trail.png" 2638px;="" height:="" 1634px;"="" style="height: 142px; width: 230px; float: right;">Sourcetrail 2019.3 released
by Eberhard Gräther
From the article:
The Sourcetrail 2019.3 release introduces the new Custom Trail dialog to query and display connections between any two symbols. Additionally, the new release brings Precompiled Header (PCH) Support for C and C++ projects to speed up the indexing step.