Why doesn't t2 give the same result as t1?

import std.algorithm;
import std.typecons;

alias T = Tuple!(string, "key", int, "value");

auto t1 = [T("WC", 0), T("Atelye", 0),
      T("Mutfak", 41),
      T("Salon", 42)
];
assert(t1.find!"a.value > 0"
         .map!"a.key"
         .equal(["Mutfak", "Salon"])
);

auto t2 = [T("WC", 0),
      T("Mutfak", 41),
      T("Salon", 42),
      T("Atelye", 0)
];
assert(t2.find!"a.value > 0"
         .map!"a.key"
         .equal(["Mutfak", "Salon", "Atelye"])
);

On Wednesday, 4 September 2024 at 08:04:58 UTC, drug007 wrote:

Thank you, it's my mistake. We confused HOF, which has the same first letter. So, if we turn the question towards the associative array, can a similar one be done without using each or foreach? For example:

auto l2 = ["WC": 0, "Mutfak": 41,
    "Salon": 42, "Atelye": 0
  ];

  l2.values.filter!"a > 0".writeln;
  // [41, 42]
  foreach(key, value; l2)
    if(value > 0) key.write(", ");

  // Mutfak, Salon,

On Wednesday, 4 September 2024 at 08:45:04 UTC, Salih Dincer wrote:

auto l2 = ["WC": 0, "Mutfak": 41,
    "Salon": 42, "Atelye": 0
  ];

  l2.values.filter!"a > 0".writeln;
  // [41, 42]
  foreach(key, value; l2)
    if(value > 0) key.write(", ");

  // Mutfak, Salon,

Something like:

l2.byPair.filter!"a.value > 0".map!(a => a.key).writeln;

On Wednesday, 4 September 2024 at 08:58:34 UTC, Sergey wrote:

l2.byPair.filter!"a.value > 0".map!(a => a.key).writeln;

Thank you for your answers, my forum friends. For tuples that are not fully integrated into the language yet, byPair() is a nice possibility. Because you don't need to import std.typecons. Moreover, instead of a complicated syntax, associative array makes life easier. Here is an example:

import std.range, std.algorithm,
       std.stdio;

void main()
{
  //import std.array : byPair;/*
  import std.typecons : Tuple;

  alias T = Tuple!(string, "key", int, "value");
  auto list = [T("Mutfak", 41), T("WC", 0),
               T("Salon", 42),
               T("Atelye", 0)
  ];

  list.map!"a.key".writeln;
  // ["Mutfak", "WC", "Salon", "Atelye"] ✓

  /*/

  auto list = ["Mutfak": 41, "WC": 0,
               "Salon": 42,
               "Atelye": 0
  ];
  list.byPair.map!"a.key".writeln;
  // ["WC", "Mutfak", "Atelye", "Salon"] ❓
  // but the order is uncertain!

  //*/
}

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