From 81bc0884b0590e42f96e413974fc0218681787d0 Mon Sep 17 00:00:00 2001
From: Neven Sajko <s@purelymail.com>
Date: Wed, 4 Mar 2026 14:25:38 +0100
Subject: [PATCH 1/2] simplify `firstrest` using `Iterators.peel`

`Iterators.peel` is supported on all Julia versions supported by
IterTools. In fact, it was already present with Julia v0.7.
---
 src/IterTools.jl | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/IterTools.jl b/src/IterTools.jl
index b5e62f6..543ada2 100644
--- a/src/IterTools.jl
+++ b/src/IterTools.jl
@@ -128,11 +128,9 @@ julia> collect(r)
 ```
 """
 function firstrest(xs)
-    t = iterate(xs)
+    t = Iterators.peel(xs)
     t === nothing && throw(ArgumentError("collection must be non-empty"))
-    f, s = t
-    r = Iterators.rest(xs, s)
-    return f, r
+    return t
 end
 
 # Iterate through the first n elements, throwing an exception if

From 482313a172f1635395583e986fc5b3fe2855367c Mon Sep 17 00:00:00 2001
From: Neven Sajko <s@purelymail.com>
Date: Sun, 8 Mar 2026 11:31:56 +0100
Subject: [PATCH 2/2] deprecate `firstrest`

---
 src/IterTools.jl | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/IterTools.jl b/src/IterTools.jl
index 543ada2..71b1645 100644
--- a/src/IterTools.jl
+++ b/src/IterTools.jl
@@ -128,6 +128,7 @@ julia> collect(r)
 ```
 """
 function firstrest(xs)
+    Base.depwarn("`firstrest` is deprecated in favor of `Iterators.peel`", :firstrest)
     t = Iterators.peel(xs)
     t === nothing && throw(ArgumentError("collection must be non-empty"))
     return t