🐛 fix a bug due to missing overloads in ordered_map container

include/nlohmann/ordered_map.hpp

@@ -30,7 +30,7 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
     ordered_map(std::initializer_list<T> init, const Allocator& alloc = Allocator() )
         : Container{init, alloc} {}
 
-    std::pair<iterator, bool> emplace(key_type&& key, T&& t)
+    std::pair<iterator, bool> emplace(const key_type& key, T&& t)
     {
         for (auto it = this->begin(); it != this->end(); ++it)
         {
@@ -43,9 +43,40 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
         return {--this->end(), true};
     }
 
-    T& operator[](Key&& key)
+    T& operator[](const Key& key)
     {
-        return emplace(std::move(key), T{}).first->second;
+        return emplace(key, T{}).first->second;
+    }
+
+    const T& operator[](const Key& key) const
+    {
+        return at(key);
+    }
+
+    T& at(const Key& key)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it->second;
+            }
+        }
+
+        throw std::out_of_range("key not found");
+    }
+
+    const T& at(const Key& key) const
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it->second;
+            }
+        }
+
+        throw std::out_of_range("key not found");
     }
 
     size_type erase(const Key& key)

single_include/nlohmann/json.hpp

@@ -16420,7 +16420,7 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
     ordered_map(std::initializer_list<T> init, const Allocator& alloc = Allocator() )
         : Container{init, alloc} {}
 
-    std::pair<iterator, bool> emplace(key_type&& key, T&& t)
+    std::pair<iterator, bool> emplace(const key_type& key, T&& t)
     {
         for (auto it = this->begin(); it != this->end(); ++it)
         {
@@ -16433,9 +16433,40 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
         return {--this->end(), true};
     }
 
-    T& operator[](Key&& key)
+    T& operator[](const Key& key)
     {
-        return emplace(std::move(key), T{}).first->second;
+        return emplace(key, T{}).first->second;
+    }
+
+    const T& operator[](const Key& key) const
+    {
+        return at(key);
+    }
+
+    T& at(const Key& key)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it->second;
+            }
+        }
+
+        throw std::out_of_range("key not found");
+    }
+
+    const T& at(const Key& key) const
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it->second;
+            }
+        }
+
+        throw std::out_of_range("key not found");
     }
 
     size_type erase(const Key& key)

test/CMakeLists.txt

@@ -126,6 +126,7 @@ set(files
     src/unit-msgpack.cpp
     src/unit-noexcept.cpp
     src/unit-ordered_json.cpp
+    src/unit-ordered_map.cpp
     src/unit-pointer_access.cpp
     src/unit-readme.cpp
     src/unit-reference_access.cpp

test/src/unit-ordered_map.cpp

@@ -0,0 +1,125 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.9.0
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+using nlohmann::ordered_map;
+
+
+TEST_CASE("ordered_map")
+{
+    SECTION("constructor")
+    {
+        SECTION("constructor from iterator range")
+        {
+            std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
+            ordered_map<std::string, std::string> om(m.begin(), m.end());
+            CHECK(om.size() == 3);
+        }
+
+        SECTION("copy assignment")
+        {
+            std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
+            ordered_map<std::string, std::string> om(m.begin(), m.end());
+            const auto com = om;
+            CHECK(com.size() == 3);
+        }
+    }
+
+    SECTION("at")
+    {
+        std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
+        ordered_map<std::string, std::string> om(m.begin(), m.end());
+        const auto com = om;
+
+        SECTION("with Key&&")
+        {
+            CHECK(om.at(std::string("eins")) == std::string("one"));
+            CHECK(com.at(std::string("eins")) == std::string("one"));
+            CHECK_THROWS_AS(om.at(std::string("vier")), std::out_of_range);
+            CHECK_THROWS_AS(com.at(std::string("vier")), std::out_of_range);
+        }
+
+        SECTION("with const Key&&")
+        {
+            const std::string eins = "eins";
+            const std::string vier = "vier";
+            CHECK(om.at(eins) == std::string("one"));
+            CHECK(com.at(eins) == std::string("one"));
+            CHECK_THROWS_AS(om.at(vier), std::out_of_range);
+            CHECK_THROWS_AS(com.at(vier), std::out_of_range);
+        }
+
+        SECTION("with string literal")
+        {
+            CHECK(om.at("eins") == std::string("one"));
+            CHECK(com.at("eins") == std::string("one"));
+            CHECK_THROWS_AS(om.at("vier"), std::out_of_range);
+            CHECK_THROWS_AS(com.at("vier"), std::out_of_range);
+        }
+    }
+
+    SECTION("operator[]")
+    {
+        std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
+        ordered_map<std::string, std::string> om(m.begin(), m.end());
+        const auto com = om;
+
+        SECTION("with Key&&")
+        {
+            CHECK(om[std::string("eins")] == std::string("one"));
+            CHECK(com[std::string("eins")] == std::string("one"));
+
+            CHECK(om[std::string("vier")] == std::string(""));
+            CHECK(om.size() == 4);
+        }
+
+        SECTION("with const Key&&")
+        {
+            const std::string eins = "eins";
+            const std::string vier = "vier";
+
+            CHECK(om[eins] == std::string("one"));
+            CHECK(com[eins] == std::string("one"));
+
+            CHECK(om[vier] == std::string(""));
+            CHECK(om.size() == 4);
+        }
+
+        SECTION("with string literal")
+        {
+            CHECK(om["eins"] == std::string("one"));
+            CHECK(com["eins"] == std::string("one"));
+
+            CHECK(om["vier"] == std::string(""));
+            CHECK(om.size() == 4);
+        }
+    }
+}

test/src/unit-regression.cpp

@@ -1976,6 +1976,25 @@ TEST_CASE("regression tests")
         json result = json::from_cbor(data, true, false);
         CHECK(result.is_discarded());
     }
+
+    SECTION("issue #2315 - json.update and vector<pair>does not work with ordered_json")
+    {
+        nlohmann::ordered_json jsonAnimals = {{"animal", "dog"}};
+        nlohmann::ordered_json jsonCat = {{"animal", "cat"}};
+        jsonAnimals.update(jsonCat);
+        CHECK(jsonAnimals["animal"] == "cat");
+
+        std::vector<std::pair<std::string, int64_t>> intData = {std::make_pair("aaaa", 11),
+                                                                std::make_pair("bbb", 222)
+                                                               };
+        nlohmann::ordered_json jsonObj;
+        for (const auto& data : intData)
+        {
+            jsonObj[data.first] = data.second;
+        }
+        CHECK(jsonObj["aaaa"] == 11);
+        CHECK(jsonObj["bbb"] == 222);
+    }
 }
 
 #if !defined(JSON_NOEXCEPTION)