Added support for basic_string<char, traits, allocator> (closes #1045)

test/Misc/StringAdapters.cpp

@@ -4,6 +4,7 @@
 
 #include <ArduinoJson.h>
 #include <catch.hpp>
+#include "custom_string.hpp"
 
 using namespace ARDUINOJSON_NAMESPACE;
 
@@ -31,9 +32,9 @@ TEST_CASE("ConstRamStringAdapter") {
   }
 }
 
-TEST_CASE("StlString") {
+TEST_CASE("std::string") {
   std::string str("bravo");
-  StlStringAdapter adapter(str);
+  StlStringAdapter<std::string> adapter = adaptString(str);
 
   REQUIRE(adapter.compare(NULL) > 0);
   REQUIRE(adapter.compare("alpha") > 0);
@@ -43,3 +44,30 @@ TEST_CASE("StlString") {
   REQUIRE(adapter.equals("bravo"));
   REQUIRE_FALSE(adapter.equals("charlie"));
 }
+
+TEST_CASE("custom_string") {
+  custom_string str("bravo");
+  StlStringAdapter<custom_string> adapter = adaptString(str);
+
+  REQUIRE(adapter.compare(NULL) > 0);
+  REQUIRE(adapter.compare("alpha") > 0);
+  REQUIRE(adapter.compare("bravo") == 0);
+  REQUIRE(adapter.compare("charlie") < 0);
+
+  REQUIRE(adapter.equals("bravo"));
+  REQUIRE_FALSE(adapter.equals("charlie"));
+}
+
+TEST_CASE("IsString<T>") {
+  SECTION("std::string") {
+    REQUIRE(IsString<std::string>::value == true);
+  }
+
+  SECTION("basic_string<wchar_t>") {
+    REQUIRE(IsString<std::basic_string<wchar_t> >::value == false);
+  }
+
+  SECTION("custom_string") {
+    REQUIRE(IsString<custom_string>::value == true);
+  }
+}

test/Misc/StringWriter.cpp

@@ -4,6 +4,7 @@
 
 #include <ArduinoJson.h>
 #include <catch.hpp>
+#include "custom_string.hpp"
 
 using namespace ARDUINOJSON_NAMESPACE;
 
@@ -48,8 +49,30 @@ TEST_CASE("StaticStringWriter") {
   }
 }
 
-TEST_CASE("DynamicStringWriter") {
+TEST_CASE("DynamicStringWriter<std::string>") {
   std::string output;
   DynamicStringWriter<std::string> sb(output);
   common_tests(sb, output);
 }
+
+TEST_CASE("DynamicStringWriter<custom_string>") {
+  custom_string output;
+  DynamicStringWriter<custom_string> sb(output);
+
+  REQUIRE(4 == print(sb, "ABCD"));
+  REQUIRE("ABCD" == output);
+}
+
+TEST_CASE("IsWriteableString") {
+  SECTION("std::string") {
+    REQUIRE(IsWriteableString<std::string>::value == true);
+  }
+
+  SECTION("custom_string") {
+    REQUIRE(IsWriteableString<custom_string>::value == true);
+  }
+
+  SECTION("basic_string<wchar_t>") {
+    REQUIRE(IsWriteableString<std::basic_string<wchar_t> >::value == false);
+  }
+}

test/Misc/custom_string.hpp

@@ -0,0 +1,14 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#pragma once
+
+#include <string>
+
+using namespace ARDUINOJSON_NAMESPACE;
+
+struct custom_char_traits : std::char_traits<char> {};
+struct custom_allocator : std::allocator<char> {};
+typedef std::basic_string<char, custom_char_traits, custom_allocator>
+    custom_string;