🔨 added fix for arrays

README.md

@@ -27,7 +27,7 @@
   - [JSON Merge Patch](#json-merge-patch)
   - [Implicit conversions](#implicit-conversions)
   - [Conversions to/from arbitrary types](#arbitrary-types-conversions)
-  - [Binary formats (CBOR, MessagePack, and UBJSON)](#binary-formats-cbor-messagepack-and-ubjson)
+  - [Binary formats (CBOR, BSON, MessagePack, and UBJSON)](#binary-formats-bson-cbor-messagepack-and-ubjson)
 - [Supported compilers](#supported-compilers)
 - [License](#license)
 - [Contact](#contact)
@@ -874,14 +874,22 @@ struct bad_serializer
 };
 ```
 
-### Binary formats (CBOR, MessagePack, and UBJSON)
+### Binary formats (CBOR, BSON, MessagePack, and UBJSON
 
-Though JSON is a ubiquitous data format, it is not a very compact format suitable for data exchange, for instance over a network. Hence, the library supports [CBOR](http://cbor.io) (Concise Binary Object Representation), [MessagePack](http://msgpack.org), and [UBJSON](http://ubjson.org) (Universal Binary JSON Specification) to efficiently encode JSON values to byte vectors and to decode such vectors.
+Though JSON is a ubiquitous data format, it is not a very compact format suitable for data exchange, for instance over a network. Hence, the library supports [BSON](http://bsonspec.org) (Binary JSON), [CBOR](http://cbor.io) (Concise Binary Object Representation), [MessagePack](http://msgpack.org), and [UBJSON](http://ubjson.org) (Universal Binary JSON Specification) to efficiently encode JSON values to byte vectors and to decode such vectors.
 
 ```cpp
 // create a JSON value
 json j = R"({"compact": true, "schema": 0})"_json;
 
+// serialize to BSON
+std::vector<std::uint8_t> v_bson = json::to_bson(j);
+
+// 0x1B, 0x00, 0x00, 0x00, 0x08, 0x63, 0x6F, 0x6D, 0x70, 0x61, 0x63, 0x74, 0x00, 0x01, 0x10, 0x73, 0x63, 0x68, 0x65, 0x6D, 0x61, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+
+// roundtrip
+json j_from_bson = json::from_bson(v_bson);
+
 // serialize to CBOR
 std::vector<std::uint8_t> v_cbor = json::to_cbor(j);
 
@@ -1138,6 +1146,8 @@ I deeply appreciate the help of the following people.
 - [Henry Schreiner](https://github.com/henryiii) added support for GCC 4.8.
 - [knilch](https://github.com/knilch0r) made sure the test suite does not stall when run in the wrong directory.
 - [Antonio Borondo](https://github.com/antonioborondo) fixed an MSVC 2017 warning.
+- [efp](https://github.com/efp) added line and column information to parse errors.
+- [julian-becker](https://github.com/julian-becker) added BSON support.
 
 Thanks a lot for helping out! Please [let me know](mailto:mail@nlohmann.me) if I forgot someone.
 

include/nlohmann/detail/output/binary_writer.hpp

@@ -875,10 +875,11 @@ class binary_writer
     static std::size_t calc_bson_array_size(const typename BasicJsonType::array_t& value)
     {
         std::size_t embedded_document_size = 0ul;
+        std::size_t array_index = 0ul;
 
         for (const auto& el : value)
         {
-            embedded_document_size += calc_bson_element_size("", el);
+            embedded_document_size += calc_bson_element_size(std::to_string(array_index++), el);
         }
 
         return sizeof(std::int32_t) + embedded_document_size + 1ul;
@@ -893,9 +894,11 @@ class binary_writer
         write_bson_entry_header(name, 0x04); // array
         write_number<std::int32_t, true>(static_cast<std::int32_t>(calc_bson_array_size(value)));
 
+        std::size_t array_index = 0ul;
+
         for (const auto& el : value)
         {
-            write_bson_element("", el);
+            write_bson_element(std::to_string(array_index++), el);
         }
 
         oa->write_character(static_cast<CharType>(0x00));

single_include/nlohmann/json.hpp

@@ -9155,10 +9155,11 @@ class binary_writer
     static std::size_t calc_bson_array_size(const typename BasicJsonType::array_t& value)
     {
         std::size_t embedded_document_size = 0ul;
+        std::size_t array_index = 0ul;
 
         for (const auto& el : value)
         {
-            embedded_document_size += calc_bson_element_size("", el);
+            embedded_document_size += calc_bson_element_size(std::to_string(array_index++), el);
         }
 
         return sizeof(std::int32_t) + embedded_document_size + 1ul;
@@ -9173,9 +9174,11 @@ class binary_writer
         write_bson_entry_header(name, 0x04); // array
         write_number<std::int32_t, true>(static_cast<std::int32_t>(calc_bson_array_size(value)));
 
+        std::size_t array_index = 0ul;
+
         for (const auto& el : value)
         {
-            write_bson_element("", el);
+            write_bson_element(std::to_string(array_index++), el);
         }
 
         oa->write_character(static_cast<CharType>(0x00));

test/src/unit-bson.cpp

@@ -483,19 +483,19 @@ TEST_CASE("BSON")
 
             std::vector<uint8_t> expected =
             {
-                0x41, 0x00, 0x00, 0x00, // size (little endian)
+                0x49, 0x00, 0x00, 0x00, // size (little endian)
                 0x04, /// entry: embedded document
                 'e', 'n', 't', 'r', 'y', '\x00',
 
-                0x35, 0x00, 0x00, 0x00, // size (little endian)
-                0x10, 0x00, 0x01, 0x00, 0x00, 0x00,
-                0x10, 0x00, 0x02, 0x00, 0x00, 0x00,
-                0x10, 0x00, 0x03, 0x00, 0x00, 0x00,
-                0x10, 0x00, 0x04, 0x00, 0x00, 0x00,
-                0x10, 0x00, 0x05, 0x00, 0x00, 0x00,
-                0x10, 0x00, 0x06, 0x00, 0x00, 0x00,
-                0x10, 0x00, 0x07, 0x00, 0x00, 0x00,
-                0x10, 0x00, 0x08, 0x00, 0x00, 0x00,
+                0x3D, 0x00, 0x00, 0x00, // size (little endian)
+                0x10, '0', 0x00, 0x01, 0x00, 0x00, 0x00,
+                0x10, '1', 0x00, 0x02, 0x00, 0x00, 0x00,
+                0x10, '2', 0x00, 0x03, 0x00, 0x00, 0x00,
+                0x10, '3', 0x00, 0x04, 0x00, 0x00, 0x00,
+                0x10, '4', 0x00, 0x05, 0x00, 0x00, 0x00,
+                0x10, '5', 0x00, 0x06, 0x00, 0x00, 0x00,
+                0x10, '6', 0x00, 0x07, 0x00, 0x00, 0x00,
+                0x10, '7', 0x00, 0x08, 0x00, 0x00, 0x00,
                 0x00, // end marker (embedded document)
 
                 0x00 // end marker
@@ -552,6 +552,7 @@ TEST_CASE("BSON")
             CHECK(parsed == expected);
             auto dumped = json::to_bson(parsed);
             CHECK(dumped == input);
+            CHECK(json::from_bson(dumped) == expected);
         }
 
         SECTION("Example 2")
@@ -561,7 +562,7 @@ TEST_CASE("BSON")
             json expected = {{"BSON", {"awesome", 5.05, 1986}}};
             CHECK(parsed == expected);
             auto dumped = json::to_bson(parsed);
-            //CHECK(dumped == input); // see https://github.com/nlohmann/json/pull/1254#issuecomment-432831216
+            CHECK(dumped == input);
             CHECK(json::from_bson(dumped) == expected);
         }
     }
@@ -1225,7 +1226,14 @@ TEST_CASE("BSON roundtrips", "[hide]")
                 {
                     std::vector<uint8_t> vec;
                     json::to_bson(j1, vec);
-                    CHECK(vec == packed);
+
+                    if (vec != packed)
+                    {
+                        // the exact serializations may differ due to the order of
+                        // object keys; in these cases, just compare whether both
+                        // serializations create the same JSON value
+                        CHECK(json::from_bson(vec) == json::from_bson(packed));
+                    }
                 }
             }
         }