Add test for adl begin/end

test/ranges-test.cc

@@ -65,6 +65,34 @@ TEST(ranges_test, format_set) {
             "{\"one\", \"two\"}");
 }
 
+namespace adl
+{
+    struct box {
+        int value;
+    };
+
+    auto begin(box & b) noexcept -> int * {
+        return std::addressof(b.value);
+    }
+
+    auto end(box & b) noexcept -> int * {
+        return std::addressof(b.value) + 1;
+    }
+
+    auto begin(const box & b) noexcept -> const int * {
+        return std::addressof(b.value);
+    }
+
+    auto end(const box & b) noexcept -> const int * {
+        return std::addressof(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)");