From 4b7b1fd21184447076118e3198a8168235b486a8 Mon Sep 17 00:00:00 2001
From: Takafumi Arakaki <aka.tkf@gmail.com>
Date: Mon, 11 Apr 2022 05:56:35 -0400
Subject: [PATCH] Document the safety properties of lazy"str"

---
 base/strings/lazy.jl | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/base/strings/lazy.jl b/base/strings/lazy.jl
index 997fea95f7fb8..c153e471693da 100644
--- a/base/strings/lazy.jl
+++ b/base/strings/lazy.jl
@@ -47,6 +47,15 @@ LazyString
 
 !!! compat "Julia 1.8"
     `lazy"str"` requires Julia 1.8 or later.
+
+# Extended help
+## Safety properties for concurrent programs
+
+A lazy string itself does not introduce any concurrency problems even if it is printed in
+multiple Julia tasks.  However, if `print` methods on a captured value can have a
+concurrency issue when invoked without synchronizations, printing the lazy string may cause
+an issue.  Furthermore, the `print` methods on the captured values may be invoked multiple
+times.
 """
 macro lazy_str(text)
     parts = Any[]