The -> is part of Kotlin’s syntax (similar to Java’s lambda expressions syntax) and can be used in 3 contexts: when expressions where it separates “matching/condition” part from “result/execution” block val greet = when(args[0]) { “Apple”, “Orange” -> “fruit” is Number -> “How many?” else -> “hi!” } lambda expressions where it separates parameters from … Read more
The % does two things, depending on its arguments. In this case, it acts as the modulo operator, meaning when its arguments are numbers, it divides the first by the second and returns the remainder. 34 % 10 == 4 since 34 divided by 10 is three, with a remainder of four. If the first … Read more
From the Haskell report, this is the syntax for allowed symbols: a | b means a or b and a<b> means a except b special -> ( | ) | , | ; | [ | ] | `| { | } symbol -> ascSymbol | uniSymbol<special | _ | : | ” | ‘> … Read more
$a &= $b is short for $a = $a & $b which is the bitwise-and operator. $a =& $b assigns $a as a reference to $b.
Note: Firstly, I realise 99% of PHP developers use the error suppression operator (I used to be one of them), so I’m expecting any PHP dev who sees this to disagree. In your opinion, is it ever valid to use the @ operator to suppress an error/warning in PHP whereas you may be handling the … Read more
The “&” denotes a reference instead of a pointer to an object (In your case a constant reference). The advantage of having a function such as foo(string const& myname) over foo(string const* myname) is that in the former case you are guaranteed that myname is non-null, since C++ does not allow NULL references. Since you … Read more
There was a huge debate about this oddity when the feature was originally designed back in C# 2.0. The problem is that C# users are completely used to this being meaningful: if(someReference == null) When extending equality to nullable value types, you have the following choices. Nullable equality is truly lifted. If one or both … Read more
You do copy initialization, and the candidate functions that are considered to do the conversions in the conversion sequence are conversion functions and converting constructors. These are in your case B(const A&) operator B() Now, that are the way you declare them. Overload resolution abstracts away from that, and transforms each candidate into a list … Read more
They come from C AFAIR from times when it was not known what special symbols are on the keyboard. So to have portable language they were defined so anyone can use C even if they used keyboard with no &, |, or ^ (etc.). Nowadays when QWERTY is a standard (with AZWERTY & co. as … Read more
Shamelessly copied [awesome] official doc (look Send messages section for more): Messages are sent to an Actor through one of the following methods. ! means “fire-and-forget”, e.g. send a message asynchronously and return immediately. Also known as tell. ? sends a message asynchronously and returns a Future representing a possible reply. Also known as ask.