How To Detect Function Overloads in C++17, std::from_chars Example

By bfilipek | Jul 24, 2019 01:35 AM | Tags: None

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How To Detect Function Overloads in C++17, std::from_chars Example

by Bartlomiej Filipek

From the article:

Working with real examples is better in most of the cases, so I like that we could show how the detection pattern works on a real function: std::from_chars. The full check used various of techniques: SFINAE, void_t, decltype, std::declval, std::true_type, std::false_type and partial template specialisation. Plus we even used if constexpr!

What Every C++ Developer Should Know to (Correctly) Define Global Constants--Jonathan Boccara

By Adrien Hamelin | Jul 23, 2019 11:50 AM | Tags: intermediate c++17

C++17 to the rescue.

What Every C++ Developer Should Know to (Correctly) Define Global Constants

by Jonathan Boccara

From the article:

Constant values are an everyday tool to make code more expressive, by putting names over values.

For example, instead of writing 10 you can write MaxNbDisplayedLines to clarify your intentions in code, with MaxNbDisplayedLines being a constant defined as being equal to 10.

Even though defining constants is such a basic tool to write clear code, their definition in C++ can be tricky and lead to surprising (and even, undefined) behaviour, in particular when making a constant accessible to several files.

Everything in this article also applies to global variables as well as global constants, but global variables are a bad practice contrary to global constants, and we should avoid using them in the first place...

std::format in C++20--Victor Zverovich

By Adrien Hamelin | Jul 23, 2019 11:38 AM | Tags: experimental community

Just great!

std::format in C++20

by Victor Zverovich

From the article:

I’m happy to announce that the Text Formatting proposal (std::format) made it into the C++20 Committee Draft at the Cologne meeting, just in time before the feature freeze. This concludes a three-year long design, implementation, and standardization effort.

Here’s a brief history of the proposal aka “what took you so long?”...

More Rules to the Regular Expression Library--Rainer Grimm

By Adrien Hamelin | Jul 23, 2019 11:36 AM | Tags: stl intermediate

Continuing.

More Rules to the Regular Expression Library

by Rainer Grimm

From the article:

There is more to write to the usage of regular expressions than I wrote in my last post The Regular Expression Library. Let's continue...

Trip report: Summer ISO C++ standards meeting (Cologne)--Herb Sutter

By Adrien Hamelin | Jul 22, 2019 08:27 AM | Tags: experimental community

Many things happened!

Trip report: Summer ISO C++ standards meeting (Cologne)

by Herb Sutter

From the article:

Obligatory comment: The C++20 Eagle has wings.

At noon today, July 20 2019, the ISO C++ committee completed its summer meeting in Cologne, Germany, hosted with thanks by Think-Cell, SIGS Datacom, SimuNova, Silexica, Meeting C++, Josuttis Eckstein, Xara, Volker Dörr, Mike Spertus, and the Standard C++ Foundation...

Quick Q: insert vs emplace vs operator[] in c++ map

By Adrien Hamelin | Jul 16, 2019 11:31 AM | Tags: stl intermediate

Quick A: the difference is in the performance and the behaviour in case an element is not already inserted.

Recently on SO:

insert vs emplace vs operator[] in c++ map

In the particular case of a map the old options were only two: operator[] and insert (different flavors of insert). So I will start explaining those...

Expressiveness, Nullable Types, and Composition (Part 1)

By Adrien Hamelin | Jul 16, 2019 11:19 AM | Tags: experimental c++17

How do you do it?

Expressiveness, Nullable Types, and Composition (Part 1)

by Rafael Varago

From the article:

We’re software developers, our mission is to provide software that solves problems. And in its essence, writing software is all about composition.

We have a big problem to solve, so we break it up into smaller pieces that can be more easily comprehended, and then we compose these smaller pieces together into working software...

The Regular Expression Library--Rainer Grimm

By Adrien Hamelin | Jul 16, 2019 11:15 AM | Tags: stl intermediate

A quick introduction.

The Regular Expression Library

by Rainer Grimm

From the article:

My original plan was it to write about the rules of the C++ Core Guidelines to the regex and chrono library, but besides the subsection title, there is no content available. I already wrote a few posts about time functionality. So I'm done. Today, I fill the gap and write about the regex library.

Maximum Drawdown in next-gen C++--Marco Arena

By Marco Arena | Jul 12, 2019 06:26 AM | Tags: c++20 c++17 advanced

A new interpretation of a classical problem:

Maximum Drawdown in next-gen C++

by Marco Arena

From the article:

In finance, the drawdown is the measure of the decline from a historical peak in some series of data (e.g. price of a stock on a certain period of time)...

Quick Q: Constructor initialization-list evaluation order

By Adrien Hamelin | Jul 11, 2019 12:43 PM | Tags: basics

Quick A: in the order of declaration in the class.

Recently on SO:

Constructor initialization-list evaluation order

It depends on the order of member variable declaration in the class. So a_ will be the first one, then b_ will be the second one in your example.