Merge f9505298de into 170b70f082

src/json.hpp

@@ -103,6 +103,36 @@ class DecimalSeparator : public std::numpunct<char>
 
 }
 
+/*!
+@brief default type for objects
+
+This type is used to store objects if no other type is provided to @ref
+basic_json via the @a ObjectType template parameter. Defaults to `std::map<Key,
+T>`.
+
+@tparam Key  type of the object keys
+@tparam T  type of the object elements
+
+@since version 2.0.0
+*/
+template<typename Key, typename T>
+using default_object_type = std::map<Key, T>;
+
+/*!
+@brief default type for arrays
+
+This type is used to store arrays if no other type is provided to @ref
+basic_json via the @a ArrayType template parameter. Defaults to
+`std::vector<T>`.
+
+@tparam T  type of the array elements
+
+@since version 2.0.0
+*/
+template<typename T>
+using default_array_type = std::vector<T>;
+
+
 /*!
 @brief a class to store JSON values
 
@@ -175,8 +205,8 @@ Format](http://rfc7159.net/rfc7159)
 @nosubgrouping
 */
 template <
-    template<typename U, typename V, typename... Args> class ObjectType = std::map,
+    template<typename Key, typename T> class ObjectType = default_object_type,
-    template<typename U, typename... Args> class ArrayType = std::vector,
+    template<typename T> class ArrayType = default_array_type,
     class StringType = std::string,
     class BooleanType = bool,
     class NumberIntegerType = std::int64_t,
@@ -270,18 +300,20 @@ class basic_json
     described below.
 
     @tparam ObjectType  the container to store objects (e.g., `std::map` or
-    `std::unordered_map`)
+    `std::unordered_map`). This container must have exactly two template
-    @tparam StringType the type of the keys or names (e.g., `std::string`). The
+    arguments: @a Key for the keys and @a V for the stored values. That is,
-    comparison function `std::less<StringType>` is used to order elements
+    `std::map` cannot be passed directly, because it has four template
-    inside the container.
+    arguments. Instead, a type alias (like @ref default_object_type) has to be
-    @tparam AllocatorType the allocator to use for objects (e.g.,
+    provided, e.g.
-    `std::allocator`)
+    @code {.cpp}
+    template<typename Key, typename V>
+    using my_object_type = std::map<Key, V>;
+    @endcode
 
     #### Default type
 
-    With the default values for @a ObjectType (`std::map`), @a StringType
+    With the default values for @a ObjectType (@ref default_object_type) and @a
-    (`std::string`), and @a AllocatorType (`std::allocator`), the default value
+    StringType (`std::string`), the default value for @a object_t is:
-    for @a object_t is:
 
     @code {.cpp}
     std::map<
@@ -340,11 +372,7 @@ class basic_json
     7159](http://rfc7159.net/rfc7159), because any order implements the
     specified "unordered" nature of JSON objects.
     */
-    using object_t = ObjectType<StringType,
+    using object_t = ObjectType<StringType, basic_json>;
-          basic_json,
-          std::less<StringType>,
-          AllocatorType<std::pair<const StringType,
-          basic_json>>>;
 
     /*!
     @brief a type for an array
@@ -356,13 +384,19 @@ class basic_json
     explained below.
 
     @tparam ArrayType  container type to store arrays (e.g., `std::vector` or
-    `std::list`)
+    `std::list`). This container must have exactly one template arguments: @a V
-    @tparam AllocatorType  allocator to use for arrays (e.g., `std::allocator`)
+    for the stored values. That is, `std::vector` cannot be passed directly,
+    because it has two template arguments. Instead, a type alias (like @ref
+    default_array_type) has to be provided, e.g.
+    @code {.cpp}
+    template<typename V>
+    using my_array_type = std::vector<V>;
+    @endcode
 
     #### Default type
 
-    With the default values for @a ArrayType (`std::vector`) and @a
+    With the default values for @a ArrayType (@ref default_array_type), the
-    AllocatorType (`std::allocator`), the default value for @a array_t is:
+    default value for @a array_t is:
 
     @code {.cpp}
     std::vector<
@@ -390,7 +424,7 @@ class basic_json
 
     @since version 1.0.0
     */
-    using array_t = ArrayType<basic_json, AllocatorType<basic_json>>;
+    using array_t = ArrayType<basic_json>;
 
     /*!
     @brief a type for a string

src/json.hpp.re2c

@@ -103,6 +103,36 @@ class DecimalSeparator : public std::numpunct<char>
 
 }
 
+/*!
+@brief default type for objects
+
+This type is used to store objects if no other type is provided to @ref
+basic_json via the @a ObjectType template parameter. Defaults to `std::map<Key,
+T>`.
+
+@tparam Key  type of the object keys
+@tparam T  type of the object elements
+
+@since version 2.0.0
+*/
+template<typename Key, typename T>
+using default_object_type = std::map<Key, T>;
+
+/*!
+@brief default type for arrays
+
+This type is used to store arrays if no other type is provided to @ref
+basic_json via the @a ArrayType template parameter. Defaults to
+`std::vector<T>`.
+
+@tparam T  type of the array elements
+
+@since version 2.0.0
+*/
+template<typename T>
+using default_array_type = std::vector<T>;
+
+
 /*!
 @brief a class to store JSON values
 
@@ -175,8 +205,8 @@ Format](http://rfc7159.net/rfc7159)
 @nosubgrouping
 */
 template <
-    template<typename U, typename V, typename... Args> class ObjectType = std::map,
+    template<typename Key, typename T> class ObjectType = default_object_type,
-    template<typename U, typename... Args> class ArrayType = std::vector,
+    template<typename T> class ArrayType = default_array_type,
     class StringType = std::string,
     class BooleanType = bool,
     class NumberIntegerType = std::int64_t,
@@ -270,18 +300,20 @@ class basic_json
     described below.
 
     @tparam ObjectType  the container to store objects (e.g., `std::map` or
-    `std::unordered_map`)
+    `std::unordered_map`). This container must have exactly two template
-    @tparam StringType the type of the keys or names (e.g., `std::string`). The
+    arguments: @a Key for the keys and @a V for the stored values. That is,
-    comparison function `std::less<StringType>` is used to order elements
+    `std::map` cannot be passed directly, because it has four template
-    inside the container.
+    arguments. Instead, a type alias (like @ref default_object_type) has to be
-    @tparam AllocatorType the allocator to use for objects (e.g.,
+    provided, e.g.
-    `std::allocator`)
+    @code {.cpp}
+    template<typename Key, typename V>
+    using my_object_type = std::map<Key, V>;
+    @endcode
 
     #### Default type
 
-    With the default values for @a ObjectType (`std::map`), @a StringType
+    With the default values for @a ObjectType (@ref default_object_type) and @a
-    (`std::string`), and @a AllocatorType (`std::allocator`), the default value
+    StringType (`std::string`), the default value for @a object_t is:
-    for @a object_t is:
 
     @code {.cpp}
     std::map<
@@ -340,11 +372,7 @@ class basic_json
     7159](http://rfc7159.net/rfc7159), because any order implements the
     specified "unordered" nature of JSON objects.
     */
-    using object_t = ObjectType<StringType,
+    using object_t = ObjectType<StringType, basic_json>;
-          basic_json,
-          std::less<StringType>,
-          AllocatorType<std::pair<const StringType,
-          basic_json>>>;
 
     /*!
     @brief a type for an array
@@ -356,13 +384,19 @@ class basic_json
     explained below.
 
     @tparam ArrayType  container type to store arrays (e.g., `std::vector` or
-    `std::list`)
+    `std::list`). This container must have exactly one template arguments: @a V
-    @tparam AllocatorType  allocator to use for arrays (e.g., `std::allocator`)
+    for the stored values. That is, `std::vector` cannot be passed directly,
+    because it has two template arguments. Instead, a type alias (like @ref
+    default_array_type) has to be provided, e.g.
+    @code {.cpp}
+    template<typename V>
+    using my_array_type = std::vector<V>;
+    @endcode
 
     #### Default type
 
-    With the default values for @a ArrayType (`std::vector`) and @a
+    With the default values for @a ArrayType (@ref default_array_type), the
-    AllocatorType (`std::allocator`), the default value for @a array_t is:
+    default value for @a array_t is:
 
     @code {.cpp}
     std::vector<
@@ -390,7 +424,7 @@ class basic_json
 
     @since version 1.0.0
     */
-    using array_t = ArrayType<basic_json, AllocatorType<basic_json>>;
+    using array_t = ArrayType<basic_json>;
 
     /*!
     @brief a type for a string

test/unit.cpp

@@ -11970,6 +11970,9 @@ TEST_CASE("RFC 7159 examples")
     }
 }
 
+template<typename Key, typename V>
+using unordered_map_type = std::unordered_map<Key, V>;
+
 TEST_CASE("Unicode", "[hide]")
 {
     SECTION("full enumeration of Unicode codepoints")
@@ -12150,8 +12153,17 @@ TEST_CASE("regression tests")
     {
         // create JSON class with nonstandard integer number type
         using custom_json =
-            nlohmann::basic_json<std::map, std::vector, std::string, bool, int32_t, uint32_t, float>;
+            nlohmann::basic_json <
+            nlohmann::default_object_type,
+            nlohmann::default_array_type,
+            std::string,
+            bool,
+            int32_t,
+            uint32_t,
+            float >;
+
         custom_json j;
+
         j["int_1"] = 1;
         // we need to cast to int to compile with Catch - the value is int32_t
         CHECK(static_cast<int>(j["int_1"]) == 1);
@@ -12271,11 +12283,16 @@ TEST_CASE("regression tests")
         CHECK(s2 == "value");
     }
 
-    SECTION("issue #146 - character following a surrogate pair is skipped")
+    SECTION("issue #146 character following a surrogate pair is skipped")
     {
         CHECK(json::parse("\"\\ud80c\\udc60abc\"").get<json::string_t>() == u8"\U00013060abc");
     }
 
+    SECTION("issue #164 - std::unordered_map cannot be used as Object Type")
+    {
+        nlohmann::basic_json<unordered_map_type> unordered_json;
+    }
+
     SECTION("issue #171 - Cannot index by key of type static constexpr const char*")
     {
         json j;
@@ -12355,17 +12372,19 @@ TEST_CASE("regression tests")
         // create JSON class with nonstandard float number type
 
         // float
-        nlohmann::basic_json<std::map, std::vector, std::string, bool, int32_t, uint32_t, float> j_float =
+        nlohmann::basic_json<nlohmann::default_object_type, nlohmann::default_array_type, std::string, bool, int32_t, uint32_t, float>
+        j_float =
             1.23e25f;
         CHECK(j_float.get<float>() == 1.23e25f);
 
         // double
-        nlohmann::basic_json<std::map, std::vector, std::string, bool, int64_t, uint64_t, double> j_double =
+        nlohmann::basic_json<nlohmann::default_object_type, nlohmann::default_array_type, std::string, bool, int64_t, uint64_t, double>
+        j_double =
             1.23e35f;
         CHECK(j_double.get<double>() == 1.23e35f);
 
         // long double
-        nlohmann::basic_json<std::map, std::vector, std::string, bool, int64_t, uint64_t, long double>
+        nlohmann::basic_json<nlohmann::default_object_type, nlohmann::default_array_type, std::string, bool, int64_t, uint64_t, long double>
         j_long_double = 1.23e45L;
         CHECK(j_long_double.get<long double>() == 1.23e45L);
     }