C++17 creates a practical use of the backward array index operator

Re:C++17 creates a practical use of the backward array index... by im3w1l on Monday April 03, 2023 @09:15PM (#35433710)

if let is such a nice way to express this

    if let Some(x) = map.get(foo) {
        bob(x)
    }

One subtle but noteworthy thing is that the idiom only mentions map by name once, which is nice if you have a very long map name, and prevents copy paste bugs where you only update one of the two mentions.

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Re:C++17 creates a practical use of the backward array index... by paulddraper on Tuesday April 04, 2023 @12:26AM (#35435068)

Scala:

    for (x <- map.get(foo)) {
      bob(x)
    }

    // or

    map.get(foo).foreach(bob)

    // or

    map.get(foo) match {
      case Some(x) => bob(x)
    }

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Re:C++17 creates a practical use of the backward array index... by olliej on Tuesday April 04, 2023 @02:59PM (#35444381)

This pattern exists in C++ as well. The specific issue here is that all these STL APIs are in terms of C++'s iterator model, and can't be replaced with a more modern "optional" style that allows this cleaner coding style :-/

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