From a8fe8becf45b520c03250bda6e6914786ee91d83 Mon Sep 17 00:00:00 2001
From: Riccardo Brugo <brugo.riccardo@gmail.com>
Date: Fri, 11 Mar 2022 20:36:39 +0100
Subject: [PATCH] Fix compilation error for ranges with ADL `begin`/`end`
 (#2807)

* Use `range_begin`/`end` to get formatted range iterators

* Add test for adl `begin`/`end`

* Apply clang-format

* Simplify tests
---
 include/fmt/ranges.h |  4 ++--
 test/ranges-test.cc  | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/include/fmt/ranges.h b/include/fmt/ranges.h
index 77089f36..edff8f96 100644
--- a/include/fmt/ranges.h
+++ b/include/fmt/ranges.h
@@ -402,8 +402,8 @@ struct formatter<
     auto out = ctx.out();
     *out++ = prefix;
     int i = 0;
-    auto it = std::begin(range);
-    auto end = std::end(range);
+    auto it = detail::range_begin(range);
+    auto end = detail::range_end(range);
     for (; it != end; ++it) {
       if (i > 0) out = detail::write_delimiter(out);
       if (custom_specs_) {
diff --git a/test/ranges-test.cc b/test/ranges-test.cc
index 8509ee79..aa910e79 100644
--- a/test/ranges-test.cc
+++ b/test/ranges-test.cc
@@ -65,6 +65,25 @@ TEST(ranges_test, format_set) {
             "{\"one\", \"two\"}");
 }
 
+namespace adl {
+struct box {
+  int value;
+};
+
+auto begin(const box& b) -> const int* {
+  return &b.value;
+}
+
+auto end(const box& b) -> const int* {
+  return &b.value + 1;
+}
+}  // namespace adl
+
+TEST(ranges_test, format_adl_begin_end) {
+  auto b = adl::box{42};
+  EXPECT_EQ(fmt::format("{}", b), "[42]");
+}
+
 TEST(ranges_test, format_pair) {
   auto p = std::pair<int, float>(42, 1.5f);
   EXPECT_EQ(fmt::format("{}", p), "(42, 1.5)");