From 18ffdd707b2e1e5dfe3407b971a3f783373afe1d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8C=97=E9=9C=B2?=
 <69190413+illusory0x0@users.noreply.github.com>
Date: Wed, 29 Jan 2025 11:23:53 +0800
Subject: [PATCH 1/3] add CCArray.of_iter

---
 src/core/CCArray.ml        | 6 ++++++
 src/core/CCArray.mli       | 5 +++++
 src/core/CCArrayLabels.mli | 5 +++++
 tests/core/t_array.ml      | 3 +++
 4 files changed, 19 insertions(+)

diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index 00c57142d..f89043685 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -466,6 +466,12 @@ let to_seq a =
 
 let to_iter a k = iter k a
 
+let of_iter (i : 'a iter) : 'a array =
+  let open CCVector in
+  let vec = create () in
+  i (push vec);
+  to_array vec
+
 let to_gen a =
   let k = ref 0 in
   fun () ->
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index d19d42523..7f0a1ce91 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -240,6 +240,11 @@ val to_iter : 'a t -> 'a iter
     in modification of the iterator.
     @since 2.8 *)
 
+val of_iter : 'a iter -> 'a t
+(** [of_iter iter] builds a array from a given [iter].
+        In the result, elements appear in the same order as they did in the source [iter].
+     @since 3.15    *)
+
 val to_seq : 'a t -> 'a Seq.t
 (** [to_seq a] returns a [Seq.t] of the elements of an array [a].
     The input array [a] is shared with the sequence and modification of it will result
diff --git a/src/core/CCArrayLabels.mli b/src/core/CCArrayLabels.mli
index 8663c7ddd..f681e4822 100644
--- a/src/core/CCArrayLabels.mli
+++ b/src/core/CCArrayLabels.mli
@@ -248,6 +248,11 @@ val to_iter : 'a t -> 'a iter
     in modification of the iterator.
     @since 2.8 *)
 
+val of_iter : 'a iter -> 'a t
+(** [of_iter iter] builds a array from a given [iter].
+        In the result, elements appear in the same order as they did in the source [iter].
+     @since 3.15    *)
+
 val to_seq : 'a t -> 'a Seq.t
 (** [to_seq a] returns a [Seq.t] of the elements of an array [a].
     The input array [a] is shared with the sequence and modification of it will result
diff --git a/tests/core/t_array.ml b/tests/core/t_array.ml
index ecc76690c..da836f054 100644
--- a/tests/core/t_array.ml
+++ b/tests/core/t_array.ml
@@ -309,3 +309,6 @@ q ~count:300 arr_arbitrary (fun a ->
     Array.sort CCInt.compare a1;
     sort_generic (module IA) ~cmp:CCInt.compare a2;
     a1 = a2)
+;;
+
+q Q.(array int) (fun a -> of_iter (to_iter a) = a)

From 765a8da8763896be475a2e511b29d13b74398d96 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8C=97=E9=9C=B2?=
 <69190413+illusory0x0@users.noreply.github.com>
Date: Thu, 30 Jan 2025 09:37:57 +0800
Subject: [PATCH 2/3] update docs

---
 src/core/CCArray.mli       | 2 +-
 src/core/CCArrayLabels.mli | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index 7f0a1ce91..e411838c7 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -243,7 +243,7 @@ val to_iter : 'a t -> 'a iter
 val of_iter : 'a iter -> 'a t
 (** [of_iter iter] builds a array from a given [iter].
         In the result, elements appear in the same order as they did in the source [iter].
-     @since 3.15    *)
+     @since NEXT_RELEASE *)
 
 val to_seq : 'a t -> 'a Seq.t
 (** [to_seq a] returns a [Seq.t] of the elements of an array [a].
diff --git a/src/core/CCArrayLabels.mli b/src/core/CCArrayLabels.mli
index f681e4822..fd6552bf4 100644
--- a/src/core/CCArrayLabels.mli
+++ b/src/core/CCArrayLabels.mli
@@ -251,7 +251,7 @@ val to_iter : 'a t -> 'a iter
 val of_iter : 'a iter -> 'a t
 (** [of_iter iter] builds a array from a given [iter].
         In the result, elements appear in the same order as they did in the source [iter].
-     @since 3.15    *)
+     @since NEXT_RELEASE *)
 
 val to_seq : 'a t -> 'a Seq.t
 (** [to_seq a] returns a [Seq.t] of the elements of an array [a].

From fd1495324a394a4836c5e1da49981b6a290b7cf3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=8C=97=E9=9C=B2?=
 <69190413+illusory0x0@users.noreply.github.com>
Date: Thu, 30 Jan 2025 10:00:48 +0800
Subject: [PATCH 3/3] add benchmark

---
 benchs/run_benchs.ml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/benchs/run_benchs.ml b/benchs/run_benchs.ml
index ca50ad18d..306a7eab3 100644
--- a/benchs/run_benchs.ml
+++ b/benchs/run_benchs.ml
@@ -1153,12 +1153,14 @@ module Iter_ = struct
   let bench_to_array n =
     let iter () = Iter.to_array Iter.(1 -- n)
     and gen () = Gen.to_array Gen.(1 -- n)
-    and oseq () = OSeq.to_array OSeq.(1 -- n) in
+    and oseq () = OSeq.to_array OSeq.(1 -- n)
+    and of_iter () = CCArray.of_iter Iter.(1 -- n) in
     B.throughputN 3 ~repeat
       [
         "iter.to_array", iter, ();
         "gen.to_array", gen, ();
         "oseq.to_array", oseq, ();
+        "ccarray.of_iter", of_iter, ();
       ]
 
   let bench_cons n =