Test custom converter for `std::vector<T>` (issue #1840)

extras/tests/Cpp11/CMakeLists.txt

@@ -15,6 +15,10 @@ if("cxx_long_long_type" IN_LIST CMAKE_CXX_COMPILE_FEATURES)
 	list(APPEND SOURCES use_long_long_0.cpp use_long_long_1.cpp)
 endif()
 
+if("cxx_range_for" IN_LIST CMAKE_CXX_COMPILE_FEATURES AND "cxx_generalized_initializers" IN_LIST CMAKE_CXX_COMPILE_FEATURES)
+	list(APPEND SOURCES stl_containers.cpp)
+endif()
+
 if(NOT SOURCES)
 	return()
 endif()
@@ -28,5 +32,5 @@ add_test(Cpp11 Cpp11Tests)
 
 set_tests_properties(Cpp11
 	PROPERTIES
-		LABELS 		"Catch"
+		LABELS "Catch"
 )

extras/tests/Cpp11/stl_containers.cpp

@@ -0,0 +1,72 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2022, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson.h>
+#include <stdint.h>
+#include <catch.hpp>
+
+#include <string>
+#include <vector>
+
+namespace ARDUINOJSON_NAMESPACE {
+template <typename T>
+struct Converter<std::vector<T> > {
+  static void toJson(const std::vector<T>& src, JsonVariant dst) {
+    JsonArray array = dst.to<JsonArray>();
+    for (T item : src)
+      array.add(item);
+  }
+
+  static std::vector<T> fromJson(JsonVariantConst src) {
+    std::vector<T> dst;
+    for (T item : src.as<JsonArrayConst>())
+      dst.push_back(item);
+    return dst;
+  }
+
+  static bool checkJson(JsonVariantConst src) {
+    JsonArrayConst array = src;
+    bool result = array;
+    for (JsonVariantConst item : array) {
+      if (!result)
+        break;
+      result = item.is<T>();
+    }
+    return result;
+  }
+};
+}  // namespace ARDUINOJSON_NAMESPACE
+
+TEST_CASE("vector<int>") {
+  SECTION("toJson") {
+    std::vector<int> v = {1, 2};
+
+    StaticJsonDocument<128> doc;
+    doc.set(v);
+    REQUIRE(doc.as<std::string>() == "[1,2]");
+  }
+
+  SECTION("fromJson") {
+    StaticJsonDocument<128> doc;
+    doc.add(1);
+    doc.add(2);
+
+    auto v = doc.as<std::vector<int> >();
+    REQUIRE(v.size() == 2);
+    CHECK(v[0] == 1);
+    CHECK(v[1] == 2);
+  }
+
+  SECTION("checkJson") {
+    StaticJsonDocument<128> doc;
+    CHECK(doc.is<std::vector<int> >() == false);
+
+    doc.add(1);
+    doc.add(2);
+    CHECK(doc.is<std::vector<int> >() == true);
+
+    doc.add("foo");
+    CHECK(doc.is<std::vector<int> >() == false);
+  }
+}