Merge branch 'develop' into feature/messagepack

CMakeLists.txt

 cmake_minimum_required(VERSION 3.0)
 
 # define the project
-project(nlohmann_json VERSION 2.0.7 LANGUAGES CXX)
+project(nlohmann_json VERSION 2.0.8 LANGUAGES CXX)
 
 enable_testing()
 

README.md

@@ -25,7 +25,7 @@ Other aspects were not so important to us:
 
 - **Memory efficiency**. Each JSON object has an overhead of one pointer (the maximal size of a union) and one enumeration element (1 byte). The default generalization uses the following C++ data types: `std::string` for strings, `int64_t`, `uint64_t` or `double` for numbers, `std::map` for objects, `std::vector` for arrays, and `bool` for Booleans. However, you can template the generalized class `basic_json` to your needs.
 
-- **Speed**. We currently implement the parser as naive [recursive descent parser](http://en.wikipedia.org/wiki/Recursive_descent_parser) with hand coded string handling. It is fast enough, but a [LALR-parser](http://en.wikipedia.org/wiki/LALR_parser) may be even faster (but would consist of more files which makes the integration harder).
+- **Speed**. There are certainly [faster JSON libraries](https://github.com/miloyip/nativejson-benchmark#parsing-time) out there. However, if your goal is to speed up your development by adding JSON support with a single header, then this library is the way to go. If you know how to use a `std::vector` or `std::map`, you are already set.
 
 See the [contribution guidelines](https://github.com/nlohmann/json/blob/master/.github/CONTRIBUTING.md#please-dont) for more information.
 
@@ -130,6 +130,8 @@ json array_not_object = { json::array({"currency", "USD"}), json::array({"value"
 
 ### Serialization / Deserialization
 
+#### To/from strings
+
 You can create an object (deserialization) by appending `_json` to a string literal:
 
 ```cpp
@@ -163,6 +165,8 @@ std::cout << j.dump(4) << std::endl;
 // }
 ```
 
+#### To/from streams (e.g. files, string streams)
+
 You can also use streams to serialize and deserialize:
 
 ```cpp
@@ -177,10 +181,37 @@ std::cout << j;
 std::cout << std::setw(4) << j << std::endl;
 ```
 
-These operators work for any subclasses of `std::istream` or `std::ostream`.
+These operators work for any subclasses of `std::istream` or `std::ostream`. Here is the same example with files:
+
+```cpp
+// read a JSON file
+std::ifstream i("file.json");
+json j;
+i >> j;
+
+// write prettified JSON to another file
+std::ofstream o("pretty.json");
+o << std::setw(4) << j << std::endl;
+```
 
 Please note that setting the exception bit for `failbit` is inappropriate for this use case. It will result in program termination due to the `noexcept` specifier in use.
 
+#### Read from iterator range
+
+You can also read JSON from an iterator range; that is, from any container accessible by iterators whose content is stored as contiguous byte sequence, for instance a `std::vector<uint8_t>`:
+
+```cpp
+std::vector<uint8_t> v = {'t', 'r', 'u', 'e'};
+json j = json::parse(v.begin(), v.end());
+```
+
+You may leave the iterators for the range [begin, end):
+
+```cpp
+std::vector<uint8_t> v = {'t', 'r', 'u', 'e'};
+json j = json::parse(v);
+```
+
 
 ### STL-like access
 
@@ -193,6 +224,9 @@ j.push_back("foo");
 j.push_back(1);
 j.push_back(true);
 
+// also use emplace_back
+j.emplace_back(1.78);
+
 // iterate the array
 for (json::iterator it = j.begin(); it != j.end(); ++it) {
   std::cout << *it << '\n';
@@ -231,6 +265,9 @@ o["foo"] = 23;
 o["bar"] = false;
 o["baz"] = 3.141;
 
+// also use emplace
+o.emplace("weather", "sunny");
+
 // special iterator member functions for objects
 for (json::iterator it = o.begin(); it != o.end(); ++it) {
   std::cout << it.key() << " : " << it.value() << "\n";
@@ -498,7 +535,7 @@ I deeply appreciate the help of the following people.
 - [Vladimir Petrigo](https://github.com/vpetrigo) made a SFINAE hack more readable.
 - [Denis Andrejew](https://github.com/seeekr) fixed a grammar issue in the README file.
 - [Pierre-Antoine Lacaze](https://github.com/palacaze) found a subtle bug in the `dump()` function.
-- [TurpentineDistillery](https://github.com/TurpentineDistillery) pointed to [`std::locale::classic()`](http://en.cppreference.com/w/cpp/locale/locale/classic) to avoid too much locale joggling.
+- [TurpentineDistillery](https://github.com/TurpentineDistillery) pointed to [`std::locale::classic()`](http://en.cppreference.com/w/cpp/locale/locale/classic) to avoid too much locale joggling, found some nice performance improvements in the parser and improved the benchmarking code.
 - [cgzones](https://github.com/cgzones) had an idea how to fix the Coverity scan.
 
 Thanks a lot for helping out!
@@ -523,7 +560,7 @@ To compile and run the tests, you need to execute
 $ make check
 
 ===============================================================================
-All tests passed (8905491 assertions in 36 test cases)
+All tests passed (8905518 assertions in 36 test cases)
 ```
 
 Alternatively, you can use [CMake](https://cmake.org) and run

doc/Doxyfile

@@ -5,7 +5,7 @@
 #---------------------------------------------------------------------------
 DOXYFILE_ENCODING      = UTF-8
 PROJECT_NAME           = "JSON for Modern C++"
-PROJECT_NUMBER         = 2.0.7
+PROJECT_NUMBER         = 2.0.8
 PROJECT_BRIEF          = 
 PROJECT_LOGO           =
 OUTPUT_DIRECTORY       = .

doc/examples/README.link

-<a target="_blank" href="http://melpon.org/wandbox/permlink/fsf5FqYe6GoX68W6"><b>online</b></a>
\ No newline at end of file
+<a target="_blank" href="http://melpon.org/wandbox/permlink/G6Pdtdxq01HJvvJz"><b>online</b></a>
\ No newline at end of file

doc/examples/emplace.cpp

+#include <json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create JSON values
+    json object = {{"one", 1}, {"two", 2}};
+    json null;
+
+    // print values
+    std::cout << object << '\n';
+    std::cout << null << '\n';
+
+    // add values
+    auto res1 = object.emplace("three", 3);
+    null.emplace("A", "a");
+    null.emplace("B", "b");
+
+    // the following call will not add an object, because there is already
+    // a value stored at key "B"
+    auto res2 = null.emplace("B", "c");
+
+    // print values
+    std::cout << object << '\n';
+    std::cout << *res1.first << " " << std::boolalpha << res1.second << '\n';
+
+    std::cout << null << '\n';
+    std::cout << *res2.first << " " << std::boolalpha << res2.second << '\n';
+}

doc/examples/emplace.link

+<a target="_blank" href="http://melpon.org/wandbox/permlink/B6ILaoysGMliouEO"><b>online</b></a>
\ No newline at end of file

doc/examples/emplace.output

+{"one":1,"two":2}
+null
+{"one":1,"three":3,"two":2}
+3 true
+{"A":"a","B":"b"}
+"b" false

doc/examples/emplace_back.cpp

+#include <json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create JSON values
+    json array = {1, 2, 3, 4, 5};
+    json null;
+
+    // print values
+    std::cout << array << '\n';
+    std::cout << null << '\n';
+
+    // add values
+    array.emplace_back(6);
+    null.emplace_back("first");
+    null.emplace_back(3, "second");
+
+    // print values
+    std::cout << array << '\n';
+    std::cout << null << '\n';
+}

doc/examples/emplace_back.link

+<a target="_blank" href="http://melpon.org/wandbox/permlink/jdch45YEMX94DvlH"><b>online</b></a>
\ No newline at end of file

doc/examples/emplace_back.output

+[1,2,3,4,5]
+null
+[1,2,3,4,5,6]
+["first",["second","second","second"]]

doc/index.md

@@ -197,7 +197,7 @@ The container functions known from STL have been extended to support the differe
     <td class="ok_green">@link nlohmann::basic_json::max_size `max_size` @endlink (returns `0`)</td>
   </tr>
   <tr>
-    <td rowspan="5">modifiers</td>
+    <td rowspan="6">modifiers</td>
     <td>`clear`</td>
     <td class="ok_green">@link nlohmann::basic_json::clear `clear` @endlink</td>
     <td class="ok_green">@link nlohmann::basic_json::clear `clear` @endlink</td>
@@ -233,6 +233,15 @@ The container functions known from STL have been extended to support the differe
     <td class="nok_throws">throws `std::domain_error`</td>
     <td class="ok_green">@link nlohmann::basic_json::push_back(const typename object_t::value_type & val) `push_back` @endlink (creates object)<br>@link nlohmann::basic_json::push_back(const nlohmann::basic_json &) `push_back` @endlink (creates array)</td>
   </tr>
+  <tr>
+    <td>`emplace` / `emplace_back`</td>
+    <td class="ok_green">@link nlohmann::basic_json::emplace() `emplace` @endlink</td>
+    <td class="ok_green">@link nlohmann::basic_json::emplace_back() `emplace_back` @endlink</td>
+    <td class="nok_throws">throws `std::domain_error`</td>
+    <td class="nok_throws">throws `std::domain_error`</td>
+    <td class="nok_throws">throws `std::domain_error`</td>
+    <td class="ok_green">@link nlohmann::basic_json::emplace() `emplace` @endlink (creates object)<br>@link nlohmann::basic_json::emplace_back() `emplace_back` @endlink (creates array)</td>
+  </tr>
   <tr>
     <td>`swap`</td>
     <td class="ok_green">@link nlohmann::basic_json::swap `swap` @endlink</td>
@@ -268,4 +277,4 @@ The container functions known from STL have been extended to support the differe
 @author [Niels Lohmann](http://nlohmann.me)
 @see https://github.com/nlohmann/json to download the source code
 
-@version 2.0.7
+@version 2.0.8

src/json.hpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
@@ -5032,6 +5032,102 @@ class basic_json
         return *this;
     }
 
+    /*!
+    @brief add an object to an array
+
+    Creates a JSON value from the passed parameters @a args to the end of the
+    JSON value. If the function is called on a JSON null value, an empty array
+    is created before appending the value created from @a args.
+
+    @param[in] args arguments to forward to a constructor of @ref basic_json
+    @tparam Args compatible types to create a @ref basic_json object
+
+    @throw std::domain_error when called on a type other than JSON array or
+    null; example: `"cannot use emplace_back() with number"`
+
+    @complexity Amortized constant.
+
+    @liveexample{The example shows how `push_back()` can be used to add
+    elements to a JSON array. Note how the `null` value was silently converted
+    to a JSON array.,emplace_back}
+
+    @since version 2.0.8
+    */
+    template<class... Args>
+    void emplace_back(Args&& ... args)
+    {
+        // emplace_back only works for null objects or arrays
+        if (not(is_null() or is_array()))
+        {
+            throw std::domain_error("cannot use emplace_back() with " + type_name());
+        }
+
+        // transform null object into an array
+        if (is_null())
+        {
+            m_type = value_t::array;
+            m_value = value_t::array;
+            assert_invariant();
+        }
+
+        // add element to array (perfect forwarding)
+        m_value.array->emplace_back(std::forward<Args>(args)...);
+    }
+
+    /*!
+    @brief add an object to an object if key does not exist
+
+    Inserts a new element into a JSON object constructed in-place with the given
+    @a args if there is no element with the key in the container. If the
+    function is called on a JSON null value, an empty object is created before
+    appending the value created from @a args.
+
+    @param[in] args arguments to forward to a constructor of @ref basic_json
+    @tparam Args compatible types to create a @ref basic_json object
+
+    @return a pair consisting of an iterator to the inserted element, or the
+            already-existing element if no insertion happened, and a bool
+            denoting whether the insertion took place.
+
+    @throw std::domain_error when called on a type other than JSON object or
+    null; example: `"cannot use emplace() with number"`
+
+    @complexity Logarithmic in the size of the container, O(log(`size()`)).
+
+    @liveexample{The example shows how `emplace()` can be used to add elements
+    to a JSON object. Note how the `null` value was silently converted to a
+    JSON object. Further note how no value is added if there was already one
+    value stored with the same key.,emplace}
+
+    @since version 2.0.8
+    */
+    template<class... Args>
+    std::pair<iterator, bool> emplace(Args&& ... args)
+    {
+        // emplace only works for null objects or arrays
+        if (not(is_null() or is_object()))
+        {
+            throw std::domain_error("cannot use emplace() with " + type_name());
+        }
+
+        // transform null object into an object
+        if (is_null())
+        {
+            m_type = value_t::object;
+            m_value = value_t::object;
+            assert_invariant();
+        }
+
+        // add element to array (perfect forwarding)
+        auto res = m_value.object->emplace(std::forward<Args>(args)...);
+        // create result iterator and set iterator to the result of emplace
+        auto it = begin();
+        it.m_it.object_iterator = res.first;
+
+        // return pair of iterator and boolean
+        return {it, res.second};
+    }
+
     /*!
     @brief inserts element
 
@@ -9771,8 +9867,22 @@ basic_json_parser_66:
         */
         void fill_line_buffer(size_t n = 0)
         {
+            // if line buffer is used, m_content points to its data
+            assert(m_line_buffer.empty()
+                   or m_content == reinterpret_cast<const lexer_char_t*>(m_line_buffer.data()));
+
+            // if line buffer is used, m_limit is set past the end of its data
+            assert(m_line_buffer.empty()
+                   or m_limit == m_content + m_line_buffer.size());
+
+            // pointer relationships
+            assert(m_content <= m_start);
+            assert(m_start <= m_cursor);
+            assert(m_cursor <= m_limit);
+            assert(m_marker == nullptr or m_marker  <= m_limit);
+
             // number of processed characters (p)
-            const auto offset_start = m_start - m_content;
+            const size_t num_processed_chars = static_cast<size_t>(m_start - m_content);
             // offset for m_marker wrt. to m_start
             const auto offset_marker = (m_marker == nullptr) ? 0 : m_marker - m_start;
             // number of unprocessed characters (u)
@@ -9781,17 +9891,10 @@ basic_json_parser_66:
             // no stream is used or end of file is reached
             if (m_stream == nullptr or m_stream->eof())
             {
-                // skip this part if we are already using the line buffer
-                if (m_start != reinterpret_cast<const lexer_char_t*>(m_line_buffer.data()))
-                {
-                    // copy unprocessed characters to line buffer
-                    m_line_buffer.clear();
-                    for (m_cursor = m_start; m_cursor != m_limit; ++m_cursor)
-                    {
-                        assert(m_cursor != nullptr);
-                        m_line_buffer.append(1, static_cast<const char>(*m_cursor));
-                    }
-                }
+                // m_start may or may not be pointing into m_line_buffer at
+                // this point. We trust the standand library to do the right
+                // thing. See http://stackoverflow.com/q/28142011/266378
+                m_line_buffer.assign(m_start, m_limit);
 
                 // append n characters to make sure that there is sufficient
                 // space between m_cursor and m_limit
@@ -9804,16 +9907,18 @@ basic_json_parser_66:
             else
             {
                 // delete processed characters from line buffer
-                m_line_buffer.erase(0, static_cast<size_t>(offset_start));
+                m_line_buffer.erase(0, num_processed_chars);
                 // read next line from input stream
-                std::string line;
-                std::getline(*m_stream, line, '\n');
+                m_line_buffer_tmp.clear();
+                std::getline(*m_stream, m_line_buffer_tmp, '\n');
+
                 // add line with newline symbol to the line buffer
-                m_line_buffer += line + "\n";
+                m_line_buffer += m_line_buffer_tmp;
+                m_line_buffer.push_back('\n');
             }
 
             // set pointers
-            m_content = reinterpret_cast<const lexer_char_t*>(m_line_buffer.c_str());
+            m_content = reinterpret_cast<const lexer_char_t*>(m_line_buffer.data());
             assert(m_content != nullptr);
             m_start  = m_content;
             m_marker = m_start + offset_marker;
@@ -9896,9 +10001,20 @@ basic_json_parser_66:
             // iterate the result between the quotes
             for (const lexer_char_t* i = m_start + 1; i < m_cursor - 1; ++i)
             {
-                // process escaped characters
-                if (*i == '\\')
+                // find next escape character
+                auto e = std::find(i, m_cursor - 1, '\\');
+                if (e != i)
                 {
+                    // see https://github.com/nlohmann/json/issues/365#issuecomment-262874705
+                    for (auto k = i; k < e; k++)
+                    {
+                        result.push_back(static_cast<typename string_t::value_type>(*k));
+                    }
+                    i = e - 1; // -1 because of ++i
+                }
+                else
+                {
+                    // processing escaped character
                     // read next character
                     ++i;
 
@@ -9985,12 +10101,6 @@ basic_json_parser_66:
                         }
                     }
                 }
-                else
-                {
-                    // all other characters are just copied to the end of the
-                    // string
-                    result.append(1, static_cast<typename string_t::value_type>(*i));
-                }
             }
 
             return result;
@@ -10174,6 +10284,8 @@ basic_json_parser_66:
         std::istream* m_stream = nullptr;
         /// line buffer buffer for m_stream
         string_t m_line_buffer {};
+        /// used for filling m_line_buffer
+        string_t m_line_buffer_tmp {};
         /// the buffer pointer
         const lexer_char_t* m_content = nullptr;
         /// pointer to the beginning of the current symbol

src/json.hpp.re2c

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
@@ -5032,6 +5032,102 @@ class basic_json
         return *this;
     }
 
+    /*!
+    @brief add an object to an array
+
+    Creates a JSON value from the passed parameters @a args to the end of the
+    JSON value. If the function is called on a JSON null value, an empty array
+    is created before appending the value created from @a args.
+
+    @param[in] args arguments to forward to a constructor of @ref basic_json
+    @tparam Args compatible types to create a @ref basic_json object
+
+    @throw std::domain_error when called on a type other than JSON array or
+    null; example: `"cannot use emplace_back() with number"`
+
+    @complexity Amortized constant.
+
+    @liveexample{The example shows how `push_back()` can be used to add
+    elements to a JSON array. Note how the `null` value was silently converted
+    to a JSON array.,emplace_back}
+
+    @since version 2.0.8
+    */
+    template<class... Args>
+    void emplace_back(Args&& ... args)
+    {
+        // emplace_back only works for null objects or arrays
+        if (not(is_null() or is_array()))
+        {
+            throw std::domain_error("cannot use emplace_back() with " + type_name());
+        }
+
+        // transform null object into an array
+        if (is_null())
+        {
+            m_type = value_t::array;
+            m_value = value_t::array;
+            assert_invariant();
+        }
+
+        // add element to array (perfect forwarding)
+        m_value.array->emplace_back(std::forward<Args>(args)...);
+    }
+
+    /*!
+    @brief add an object to an object if key does not exist
+
+    Inserts a new element into a JSON object constructed in-place with the given
+    @a args if there is no element with the key in the container. If the
+    function is called on a JSON null value, an empty object is created before
+    appending the value created from @a args.
+
+    @param[in] args arguments to forward to a constructor of @ref basic_json
+    @tparam Args compatible types to create a @ref basic_json object
+
+    @return a pair consisting of an iterator to the inserted element, or the
+            already-existing element if no insertion happened, and a bool
+            denoting whether the insertion took place.
+
+    @throw std::domain_error when called on a type other than JSON object or
+    null; example: `"cannot use emplace() with number"`
+
+    @complexity Logarithmic in the size of the container, O(log(`size()`)).
+
+    @liveexample{The example shows how `emplace()` can be used to add elements
+    to a JSON object. Note how the `null` value was silently converted to a
+    JSON object. Further note how no value is added if there was already one
+    value stored with the same key.,emplace}
+
+    @since version 2.0.8
+    */
+    template<class... Args>
+    std::pair<iterator, bool> emplace(Args&& ... args)
+    {
+        // emplace only works for null objects or arrays
+        if (not(is_null() or is_object()))
+        {
+            throw std::domain_error("cannot use emplace() with " + type_name());
+        }
+
+        // transform null object into an object
+        if (is_null())
+        {
+            m_type = value_t::object;
+            m_value = value_t::object;
+            assert_invariant();
+        }
+
+        // add element to array (perfect forwarding)
+        auto res = m_value.object->emplace(std::forward<Args>(args)...);
+        // create result iterator and set iterator to the result of emplace
+        auto it = begin();
+        it.m_it.object_iterator = res.first;
+
+        // return pair of iterator and boolean
+        return {it, res.second};
+    }
+
     /*!
     @brief inserts element
 
@@ -8921,8 +9017,22 @@ class basic_json
         */
         void fill_line_buffer(size_t n = 0)
         {
+            // if line buffer is used, m_content points to its data
+            assert(m_line_buffer.empty()
+                   or m_content == reinterpret_cast<const lexer_char_t*>(m_line_buffer.data()));
+
+            // if line buffer is used, m_limit is set past the end of its data
+            assert(m_line_buffer.empty()
+                   or m_limit == m_content + m_line_buffer.size());
+
+            // pointer relationships
+            assert(m_content <= m_start);
+            assert(m_start <= m_cursor);
+            assert(m_cursor <= m_limit);
+            assert(m_marker == nullptr or m_marker  <= m_limit);
+
             // number of processed characters (p)
-            const auto offset_start = m_start - m_content;
+            const size_t num_processed_chars = static_cast<size_t>(m_start - m_content);
             // offset for m_marker wrt. to m_start
             const auto offset_marker = (m_marker == nullptr) ? 0 : m_marker - m_start;
             // number of unprocessed characters (u)
@@ -8931,17 +9041,10 @@ class basic_json
             // no stream is used or end of file is reached
             if (m_stream == nullptr or m_stream->eof())
             {
-                // skip this part if we are already using the line buffer
-                if (m_start != reinterpret_cast<const lexer_char_t*>(m_line_buffer.data()))
-                {
-                    // copy unprocessed characters to line buffer
-                    m_line_buffer.clear();
-                    for (m_cursor = m_start; m_cursor != m_limit; ++m_cursor)
-                    {
-                        assert(m_cursor != nullptr);
-                        m_line_buffer.append(1, static_cast<const char>(*m_cursor));
-                    }
-                }
+                // m_start may or may not be pointing into m_line_buffer at
+                // this point. We trust the standand library to do the right
+                // thing. See http://stackoverflow.com/q/28142011/266378
+                m_line_buffer.assign(m_start, m_limit);
 
                 // append n characters to make sure that there is sufficient
                 // space between m_cursor and m_limit
@@ -8954,16 +9057,18 @@ class basic_json
             else
             {
                 // delete processed characters from line buffer
-                m_line_buffer.erase(0, static_cast<size_t>(offset_start));
+                m_line_buffer.erase(0, num_processed_chars);
                 // read next line from input stream
-                std::string line;
-                std::getline(*m_stream, line, '\n');
+                m_line_buffer_tmp.clear();
+                std::getline(*m_stream, m_line_buffer_tmp, '\n');
+
                 // add line with newline symbol to the line buffer
-                m_line_buffer += line + "\n";
+                m_line_buffer += m_line_buffer_tmp;
+                m_line_buffer.push_back('\n');
             }
 
             // set pointers
-            m_content = reinterpret_cast<const lexer_char_t*>(m_line_buffer.c_str());
+            m_content = reinterpret_cast<const lexer_char_t*>(m_line_buffer.data());
             assert(m_content != nullptr);
             m_start  = m_content;
             m_marker = m_start + offset_marker;
@@ -9046,9 +9151,20 @@ class basic_json
             // iterate the result between the quotes
             for (const lexer_char_t* i = m_start + 1; i < m_cursor - 1; ++i)
             {
-                // process escaped characters
-                if (*i == '\\')
+                // find next escape character
+                auto e = std::find(i, m_cursor - 1, '\\');
+                if (e != i)
                 {
+                    // see https://github.com/nlohmann/json/issues/365#issuecomment-262874705
+                    for (auto k = i; k < e; k++)
+                    {
+                        result.push_back(static_cast<typename string_t::value_type>(*k));
+                    }
+                    i = e - 1; // -1 because of ++i
+                }
+                else
+                {
+                    // processing escaped character
                     // read next character
                     ++i;
 
@@ -9135,12 +9251,6 @@ class basic_json
                         }
                     }
                 }
-                else
-                {
-                    // all other characters are just copied to the end of the
-                    // string
-                    result.append(1, static_cast<typename string_t::value_type>(*i));
-                }
             }
 
             return result;
@@ -9324,6 +9434,8 @@ class basic_json
         std::istream* m_stream = nullptr;
         /// line buffer buffer for m_stream
         string_t m_line_buffer {};
+        /// used for filling m_line_buffer
+        string_t m_line_buffer_tmp {};
         /// the buffer pointer
         const lexer_char_t* m_content = nullptr;
         /// pointer to the beginning of the current symbol

test/src/fuzz.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (fuzz test support)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Run "make fuzz_testing" and follow the instructions.

test/src/unit-algorithms.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-allocator.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-capacity.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-class_const_iterator.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-class_iterator.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-class_lexer.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-class_parser.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-comparison.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-concepts.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-constructor1.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-constructor2.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-convenience.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-conversions.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-deserialization.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-element_access1.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-element_access2.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-inspection.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-iterator_wrapper.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-iterators1.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-iterators2.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-json_patch.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-json_pointer.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-modifiers.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
@@ -258,6 +258,103 @@ TEST_CASE("modifiers")
         }
     }
 
+    SECTION("emplace_back()")
+    {
+        SECTION("to array")
+        {
+            SECTION("null")
+            {
+                json j;
+                j.emplace_back(1);
+                j.emplace_back(2);
+                CHECK(j.type() == json::value_t::array);
+                CHECK(j == json({1, 2}));
+            }
+
+            SECTION("array")
+            {
+                json j = {1, 2, 3};
+                j.emplace_back("Hello");
+                CHECK(j.type() == json::value_t::array);
+                CHECK(j == json({1, 2, 3, "Hello"}));
+            }
+
+            SECTION("multiple values")
+            {
+                json j;
+                j.emplace_back(3, "foo");
+                CHECK(j.type() == json::value_t::array);
+                CHECK(j == json({{"foo", "foo", "foo"}}));
+            }
+        }
+
+        SECTION("other type")
+        {
+            json j = 1;
+            CHECK_THROWS_AS(j.emplace_back("Hello"), std::domain_error);
+            CHECK_THROWS_WITH(j.emplace_back("Hello"), "cannot use emplace_back() with number");
+        }
+    }
+
+    SECTION("emplace()")
+    {
+        SECTION("to object")
+        {
+            SECTION("null")
+            {
+                // start with a null value
+                json j;
+
+                // add a new key
+                auto res1 = j.emplace("foo", "bar");
+                CHECK(res1.second == true);
+                CHECK(*res1.first == "bar");
+
+                // the null value is changed to an object
+                CHECK(j.type() == json::value_t::object);
+
+                // add a new key
+                auto res2 = j.emplace("baz", "bam");
+                CHECK(res2.second == true);
+                CHECK(*res2.first == "bam");
+
+                // we try to insert at given key - no change
+                auto res3 = j.emplace("baz", "bad");
+                CHECK(res3.second == false);
+                CHECK(*res3.first == "bam");
+
+                // the final object
+                CHECK(j == json({{"baz", "bam"}, {"foo", "bar"}}));
+            }
+
+            SECTION("object")
+            {
+                // start with an object
+                json j = {{"foo", "bar"}};
+
+                // add a new key
+                auto res1 = j.emplace("baz", "bam");
+                CHECK(res1.second == true);
+                CHECK(*res1.first == "bam");
+
+                // add an existing key
+                auto res2 = j.emplace("foo", "bad");
+                CHECK(res2.second == false);
+                CHECK(*res2.first == "bar");
+
+                // check final object
+                CHECK(j == json({{"baz", "bam"}, {"foo", "bar"}}));
+            }
+        }
+
+        SECTION("other type")
+        {
+            json j = 1;
+            CHECK_THROWS_AS(j.emplace("foo", "bar"), std::domain_error);
+            CHECK_THROWS_WITH(j.emplace("foo", "bar"), "cannot use emplace() with number");
+        }
+    }
+
     SECTION("operator+=")
     {
         SECTION("to array")

test/src/unit-pointer_access.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-readme.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-reference_access.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-regression.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-serialization.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-testsuites.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit-unicode.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.

test/src/unit.cpp

 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 2.0.7
+|  |  |__   |  |  | | | |  version 2.0.8
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.