From d8e49e9f4ee74f6b08e82f0bf4dec7a0a8f65edb Mon Sep 17 00:00:00 2001
From: Jason Cobb <jason.e.cobb@gmail.com>
Date: Sun, 28 Feb 2021 22:42:08 -0500
Subject: [PATCH] Add test for non-default-constructible iterator

---
 test/format-test.cc | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/test/format-test.cc b/test/format-test.cc
index a71aeaf1dabc..ad2070b1b868 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -170,6 +170,27 @@ TEST(IteratorTest, TruncatingIteratorDefaultConstruct) {
   EXPECT_EQ(std::size_t{0}, it.count());
 }
 
+TEST(IteratorTest, TruncatingIteratorDeletedDefaultConstruct) {
+  struct non_default_constructible_iterator {
+    using iterator_category = std::output_iterator_tag;
+    using value_type = void;
+    using difference_type = std::ptrdiff_t;
+    using pointer = void;
+    using reference = void;
+
+    non_default_constructible_iterator() = delete;
+    
+    non_default_constructible_iterator& operator++();
+    non_default_constructible_iterator operator++(int);
+    char& operator*() const;
+  };
+
+  static_assert(
+      !std::is_default_constructible<fmt::detail::truncating_iterator<
+          non_default_constructible_iterator>>::value,
+      "");
+}
+
 #ifdef __cpp_lib_ranges
 TEST(IteratorTest, TruncatingIteratorOutputIterator) {
   static_assert(std::output_iterator<fmt::detail::truncating_iterator<char*>,