Prevent memory leak when exception is thrown in adl_serializer::to_json (#3901)

Co-authored-by: barcode <barcode@example.com>

tests/src/unit-class_const_iterator.cpp

@@ -216,28 +216,28 @@ TEST_CASE("const_iterator class")
             {
                 json const j({{"foo", "bar"}});
                 json::const_iterator it = j.cbegin();
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->begin()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->begin()));
                 it++;
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->end()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->end()));
             }
 
             SECTION("array")
             {
                 json const j({1, 2, 3, 4});
                 json::const_iterator it = j.cbegin();
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->begin()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->begin()));
                 it++;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it++;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it++;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it++;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->end()));
             }
         }
 
@@ -267,28 +267,28 @@ TEST_CASE("const_iterator class")
             {
                 json const j({{"foo", "bar"}});
                 json::const_iterator it = j.cbegin();
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->begin()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->begin()));
                 ++it;
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->end()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->end()));
             }
 
             SECTION("array")
             {
                 json const j({1, 2, 3, 4});
                 json::const_iterator it = j.cbegin();
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->begin()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->begin()));
                 ++it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 ++it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 ++it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 ++it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->end()));
             }
         }
 
@@ -316,28 +316,28 @@ TEST_CASE("const_iterator class")
             {
                 json const j({{"foo", "bar"}});
                 json::const_iterator it = j.cend();
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->end()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->end()));
                 it--;
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->begin()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->begin()));
             }
 
             SECTION("array")
             {
                 json const j({1, 2, 3, 4});
                 json::const_iterator it = j.cend();
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->end()));
                 it--;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it--;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it--;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it--;
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
             }
         }
 
@@ -365,28 +365,28 @@ TEST_CASE("const_iterator class")
             {
                 json const j({{"foo", "bar"}});
                 json::const_iterator it = j.cend();
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->end()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->end()));
                 --it;
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->begin()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->begin()));
             }
 
             SECTION("array")
             {
                 json const j({1, 2, 3, 4});
                 json::const_iterator it = j.cend();
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->end()));
                 --it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 --it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 --it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 --it;
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
             }
         }
     }

tests/src/unit-class_iterator.cpp

@@ -206,28 +206,28 @@ TEST_CASE("iterator class")
             {
                 json j({{"foo", "bar"}});
                 json::iterator it = j.begin();
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->begin()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->begin()));
                 it++;
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->end()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->end()));
             }
 
             SECTION("array")
             {
                 json j({1, 2, 3, 4});
                 json::iterator it = j.begin();
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->begin()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->begin()));
                 it++;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it++;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it++;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it++;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->end()));
             }
         }
 
@@ -257,28 +257,28 @@ TEST_CASE("iterator class")
             {
                 json j({{"foo", "bar"}});
                 json::iterator it = j.begin();
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->begin()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->begin()));
                 ++it;
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->end()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->end()));
             }
 
             SECTION("array")
             {
                 json j({1, 2, 3, 4});
                 json::iterator it = j.begin();
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->begin()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->begin()));
                 ++it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 ++it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 ++it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 ++it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->end()));
             }
         }
 
@@ -306,28 +306,28 @@ TEST_CASE("iterator class")
             {
                 json j({{"foo", "bar"}});
                 json::iterator it = j.end();
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->end()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->end()));
                 it--;
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->begin()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->begin()));
             }
 
             SECTION("array")
             {
                 json j({1, 2, 3, 4});
                 json::iterator it = j.end();
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->end()));
                 it--;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it--;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it--;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 it--;
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
             }
         }
 
@@ -355,28 +355,28 @@ TEST_CASE("iterator class")
             {
                 json j({{"foo", "bar"}});
                 json::iterator it = j.end();
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->end()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->end()));
                 --it;
-                CHECK((it.m_it.object_iterator == it.m_object->m_value.object->begin()));
+                CHECK((it.m_it.object_iterator == it.m_object->m_data.m_value.object->begin()));
             }
 
             SECTION("array")
             {
                 json j({1, 2, 3, 4});
                 json::iterator it = j.end();
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->end()));
                 --it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 --it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 --it;
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
                 --it;
-                CHECK((it.m_it.array_iterator == it.m_object->m_value.array->begin()));
-                CHECK((it.m_it.array_iterator != it.m_object->m_value.array->end()));
+                CHECK((it.m_it.array_iterator == it.m_object->m_data.m_value.array->begin()));
+                CHECK((it.m_it.array_iterator != it.m_object->m_data.m_value.array->end()));
             }
         }
     }

tests/src/unit-constructor1.cpp

@@ -872,7 +872,7 @@ TEST_CASE("constructors")
             float const n = 42.23f;
             json const j(n);
             CHECK(j.type() == json::value_t::number_float);
-            CHECK(j.m_value.number_float == Approx(j_reference.m_value.number_float));
+            CHECK(j.m_data.m_value.number_float == Approx(j_reference.m_data.m_value.number_float));
         }
 
         SECTION("double")
@@ -880,7 +880,7 @@ TEST_CASE("constructors")
             double const n = 42.23;
             json const j(n);
             CHECK(j.type() == json::value_t::number_float);
-            CHECK(j.m_value.number_float == Approx(j_reference.m_value.number_float));
+            CHECK(j.m_data.m_value.number_float == Approx(j_reference.m_data.m_value.number_float));
         }
 
         SECTION("long double")
@@ -888,28 +888,28 @@ TEST_CASE("constructors")
             long double const n = 42.23L;
             json const j(n);
             CHECK(j.type() == json::value_t::number_float);
-            CHECK(j.m_value.number_float == Approx(j_reference.m_value.number_float));
+            CHECK(j.m_data.m_value.number_float == Approx(j_reference.m_data.m_value.number_float));
         }
 
         SECTION("floating-point literal without suffix")
         {
             json const j(42.23);
             CHECK(j.type() == json::value_t::number_float);
-            CHECK(j.m_value.number_float == Approx(j_reference.m_value.number_float));
+            CHECK(j.m_data.m_value.number_float == Approx(j_reference.m_data.m_value.number_float));
         }
 
         SECTION("integer literal with f suffix")
         {
             json const j(42.23f);
             CHECK(j.type() == json::value_t::number_float);
-            CHECK(j.m_value.number_float == Approx(j_reference.m_value.number_float));
+            CHECK(j.m_data.m_value.number_float == Approx(j_reference.m_data.m_value.number_float));
         }
 
         SECTION("integer literal with l suffix")
         {
             json const j(42.23L);
             CHECK(j.type() == json::value_t::number_float);
-            CHECK(j.m_value.number_float == Approx(j_reference.m_value.number_float));
+            CHECK(j.m_data.m_value.number_float == Approx(j_reference.m_data.m_value.number_float));
         }
     }
 

tests/src/unit-conversions.cpp

@@ -1076,19 +1076,19 @@ TEST_CASE("value conversion")
         SECTION("number_float_t")
         {
             auto n = j.get<json::number_float_t>();
-            CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
+            CHECK(json(n).m_data.m_value.number_float == Approx(j.m_data.m_value.number_float));
         }
 
         SECTION("float")
         {
             auto n = j.get<float>();
-            CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
+            CHECK(json(n).m_data.m_value.number_float == Approx(j.m_data.m_value.number_float));
         }
 
         SECTION("double")
         {
             auto n = j.get<double>();
-            CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
+            CHECK(json(n).m_data.m_value.number_float == Approx(j.m_data.m_value.number_float));
         }
 
         SECTION("exception in case of a non-string type")
@@ -1126,19 +1126,19 @@ TEST_CASE("value conversion")
         SECTION("number_float_t")
         {
             json::number_float_t const n = j;
-            CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
+            CHECK(json(n).m_data.m_value.number_float == Approx(j.m_data.m_value.number_float));
         }
 
         SECTION("float")
         {
             float const n = j;
-            CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
+            CHECK(json(n).m_data.m_value.number_float == Approx(j.m_data.m_value.number_float));
         }
 
         SECTION("double")
         {
             double const n = j;
-            CHECK(json(n).m_value.number_float == Approx(j.m_value.number_float));
+            CHECK(json(n).m_data.m_value.number_float == Approx(j.m_data.m_value.number_float));
         }
     }
 #endif
@@ -1151,7 +1151,7 @@ TEST_CASE("value conversion")
         SECTION("binary_t")
         {
             json::binary_t const b = j.get<json::binary_t>();
-            CHECK(*json(b).m_value.binary == *j.m_value.binary);
+            CHECK(*json(b).m_data.m_value.binary == *j.m_data.m_value.binary);
         }
 
         SECTION("get_binary()")
@@ -1159,14 +1159,14 @@ TEST_CASE("value conversion")
             SECTION("non-const")
             {
                 auto& b = j.get_binary();
-                CHECK(*json(b).m_value.binary == *j.m_value.binary);
+                CHECK(*json(b).m_data.m_value.binary == *j.m_data.m_value.binary);
             }
 
             SECTION("non-const")
             {
                 const json j_const = j;
                 const auto& b = j_const.get_binary();
-                CHECK(*json(b).m_value.binary == *j.m_value.binary);
+                CHECK(*json(b).m_data.m_value.binary == *j.m_data.m_value.binary);
             }
         }
 
@@ -1258,7 +1258,7 @@ TEST_CASE("value conversion")
         SECTION("binary_t")
         {
             json::binary_t const b = j;
-            CHECK(*json(b).m_value.binary == *j.m_value.binary);
+            CHECK(*json(b).m_data.m_value.binary == *j.m_data.m_value.binary);
         }
     }
 #endif

tests/src/unit-no-mem-leak-on-adl-serialize.cpp

@@ -0,0 +1,86 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.11.2
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+#include <exception>
+#include <iostream>
+
+struct Foo
+{
+    int a;
+    int b;
+};
+
+namespace nlohmann
+{
+template <>
+struct adl_serializer<Foo>
+{
+    static void to_json(json& j, Foo const& f)
+    {
+        switch (f.b)
+        {
+            case 0:
+                j["a"] = f.a;
+                break;
+            case 1:
+                j[0] = f.a;
+                break;
+            default:
+                j = "test";
+        }
+        if (f.a == 1)
+        {
+            throw std::runtime_error("b is invalid");
+        }
+    }
+};
+} // namespace nlohmann
+
+TEST_CASE("check_for_mem_leak_on_adl_to_json-1")
+{
+    try
+    {
+        const nlohmann::json j = Foo {1, 0};
+        std::cout << j.dump() << "\n";
+    }
+    catch (...)
+    {
+        // just ignore the exception in this POC
+    }
+}
+
+TEST_CASE("check_for_mem_leak_on_adl_to_json-2")
+{
+    try
+    {
+        const nlohmann::json j = Foo {1, 1};
+        std::cout << j.dump() << "\n";
+    }
+    catch (...)
+    {
+        // just ignore the exception in this POC
+    }
+}
+
+TEST_CASE("check_for_mem_leak_on_adl_to_json-2")
+{
+    try
+    {
+        const nlohmann::json j = Foo {1, 2};
+        std::cout << j.dump() << "\n";
+    }
+    catch (...)
+    {
+        // just ignore the exception in this POC
+    }
+}
+
+