In a recent Computerphile video, Ian Knight talked about RAII idiom and it’s application in C++ and Rust. While the video described the general concepts, I felt different examples could be more clearly convey essence of the topic.

I’ve decided to give my own explanation to hopefully better illustrate what RAII is and how it relates to Rust’s ownership. Then again, for whatever reason I’ve decided to write it as a play with dialogue in faux Old English so it may well be even more confusing instead.

No, I haven’t gone completely mad yet and still, I write this as an appeal to stop using monospaced fonts for code (conditions may apply). While fixed-width fonts have undeniable benefits when authoring software, their use is excessive and even detrimental in certain contexts. Specifically, when displaying inline code within a paragraph of text, proportional fonts are a better choice.

Ever since Witcher games took off the franchise skyrocketed in popularity. Books, comics, TV show, games, more comics, another TV show… The story of Geralt and his marry company has been told in so many ways that it’s becoming a wee bit hard to keep track of chronology of all the events; especially across different forms of media.

In this article I’ve collected all official Witcher works ordering them in chronological order. To avoid any confusion, let me state up front that if you’re new to the franchise or haven’t read the books yet this list might not be for you. If you’re looking for the order to read the books in, I’ve prepared a separate article which describes that.

Skip right to the chronology

Or how to change language of Google website.

If you’ve travelled abroad, you may have noticed that Google tries to be helpful and uses the language of the region you’re in on its websites. It doesn’t matter if your operating system is set to Spanish, for example; Google Search will still use Portuguese if you happen to be in Brazil.

Fortunately, there’s a simple way to force Google to use a specific language. All you need to do is append ?hl=lang to the website’s address, replacing lang with a two-letter code for the desired language. For instance, ?hl=es for Spanish, ?hl=ht for Haitian, or ?hl=uk for Ukrainian.

If the URL already contains a question mark, you need to append &hl=lang instead. Additionally, if it contains a hash symbol, you need to insert the string immediately before the hash symbol. For example:

• https://www.google.com/?hl=es
• https://www.google.com/search?q=bread+sandwich&hl=es
• https://analytics.google.com/analytics/web/?hl=es#/report-home/

By the way, as a legacy of Facebook having hired many ex-Google employees, the parameter also work on some of the Facebook properties.

Without beating around the bush, the reading order for the Witcher books is as follows:

π is one of those constants which pops up when least expected. At the same time it’s sometimes missing when most needed. For example, consider the following application calculating area of a disk (not to be confused with area of a circle which is zero):

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {
	for (int i = 1; i < argc; ++i) {
		const double r = atof(argv[i]);
		printf("%f\n", M_PI * r * r);
	}
}

It uses features introduced in the 1999 edition of the C standard (often referred to as C99) so it might be good to inform the compiler of that fact with a -std=c99 flag. Unfortunately, doing so leads to an error:

$ gcc -std=c99 -o area area.c
area.c: In function ‘main’:
area.c:8:18: error: ‘M_PI’ undeclared (first use in this function)
    8 |   printf("%f\n", M_PI * r * r);
      |                  ^~~~

What’s going on? Shouldn’t math.h provide the definition of M_PI symbol? It’s what the specification claims after all. ‘glibc is broken’ some may even proclaim. In this article I’ll explain why the compiler conspire with the standard library to behave this way and why it’s the only valid thing it can do.

In a past life I’ve talked about a challenge to write the shortest program which prints all prime numbers less than a hundred. Back then I’ve discussed a 60-character long solution written in C. Since Rust is the future, inspired by a recent thread on Sieve of Eratosthenes I’ve decided to carry the task for Rust as well.

To avoid spoiling the solution, I’m padding this article with a bit of unrelated content. To jump straight to the code, skip the next block of paragraphs. Otherwise, here’s a joke for ya: