Merge upstream commits and resolve conflicts

CONTRIBUTING.md

@@ -62,6 +62,7 @@ Please understand that I cannot accept pull requests changing only file `src/jso
 - The C++11 support varies between different **compilers** and versions. Please note the [list of supported compilers](https://github.com/nlohmann/json/blob/master/README.md#supported-compilers). Some compilers like GCC 4.8 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with `#ifdef`s or other means.
 - Specifically, I am aware of compilation problems with **Microsoft Visual Studio** (there even is an [issue label](https://github.com/nlohmann/json/issues?utf8=✓&q=label%3A%22visual+studio%22+) for these kind of bugs). I understand that even in 2016, complete C++11 support isn't there yet. But please also understand that I do not want to drop features or uglify the code just to make Microsoft's sub-standard compiler happy. The past has shown that there are ways to express the functionality such that the code compiles with the most recent MSVC - unfortunately, this is not the main objective of the project.
 - Please refrain from proposing changes that would **break [JSON](http://json.org) conformance**. If you propose a conformant extension of JSON to be supported by the library, please motivate this extension.
+- Please do not open pull requests that address **multiple issues**.
 
 ## Wanted
 

README.md

@@ -388,6 +388,7 @@ I deeply appreciate the help of the following people.
 - [406345](https://github.com/406345) fixed two small warnings.
 - [Glen Fernandes](https://github.com/glenfe) noted a potential portability problem in the `has_mapped_type` function.
 - [Corbin Hughes](https://github.com/nibroc) fixed some typos in the contribution guidelines.
+- [twelsby](https://github.com/twelsby) fixed the array subscript operator and an issue that failed the MSVC build.
 
 Thanks a lot for helping out!
 
@@ -404,7 +405,7 @@ $ make
 $ ./json_unit "*"
 
 ===============================================================================
-All tests passed (3343239 assertions in 28 test cases)
+All tests passed (3343318 assertions in 29 test cases)
 ```
 
 For more information, have a look at the file [.travis.yml](https://github.com/nlohmann/json/blob/master/.travis.yml).

src/json.hpp

@@ -43,7 +43,9 @@ Class @ref nlohmann::basic_json is a good entry point for the documentation.
 #include <cassert>
 #include <ciso646>
 #include <cmath>
+#include <cstddef>
 #include <cstdio>
+#include <cstdlib>
 #include <functional>
 #include <initializer_list>
 #include <iomanip>
@@ -53,6 +55,7 @@ Class @ref nlohmann::basic_json is a good entry point for the documentation.
 #include <map>
 #include <memory>
 #include <sstream>
+#include <stdexcept>
 #include <string>
 #include <type_traits>
 #include <utility>
@@ -65,6 +68,12 @@ Class @ref nlohmann::basic_json is a good entry point for the documentation.
     #endif
 #endif
 
+// disable float-equal warnings on GCC/clang
+#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
+    #pragma GCC diagnostic push
+    #pragma GCC diagnostic ignored "-Wfloat-equal"
+#endif
+
 // enable ssize_t for MSVC
 #ifdef _MSC_VER
     #include <basetsd.h>
@@ -100,12 +109,6 @@ struct has_mapped_type
     static constexpr bool value = sizeof(test<T>(0)) == 1;
 };
 
-/// "equality" comparison for floating point numbers
-template<typename T>
-static bool approx(const T a, const T b)
-{
-    return not (a > b or a < b);
-}
 }
 
 /*!
@@ -2671,14 +2674,14 @@ class basic_json
 
     @since version 1.0.0
     */
-    template<typename ValueType, typename
+    template < typename ValueType, typename
-             std::enable_if<
+               std::enable_if <
-                 not std::is_pointer<ValueType>::value
+                   not std::is_pointer<ValueType>::value
-                 and not std::is_same<ValueType, typename string_t::value_type>::value
+                   and not std::is_same<ValueType, typename string_t::value_type>::value
 #ifndef _MSC_VER  // Fix for issue #167 operator<< abiguity under VS2015
-                 and not std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>::value
+                   and not std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>::value
 #endif
-                 , int>::type = 0>
+                   , int >::type = 0 >
     operator ValueType() const
     {
         // delegate the call to get<>() const
@@ -3062,8 +3065,6 @@ class basic_json
     the object and filled with a `null` value to make `key` a valid reference.
     In case the value was `null` before, it is converted to an object.
 
-    @note This function is required for compatibility reasons with Clang.
-
     @param[in] key  key of the element to access
 
     @return reference to the element at key @a key
@@ -3083,25 +3084,9 @@ class basic_json
     @since version 1.0.0
     */
     template<typename T, std::size_t n>
-    reference operator[](const T (&key)[n])
+    reference operator[](T * (&key)[n])
     {
-        // implicitly convert null to object
+        return operator[](static_cast<const T>(key));
-        if (is_null())
-        {
-            m_type = value_t::object;
-            m_value = value_t::object;
-        }
-
-        // at only works for objects
-        if (is_object())
-        {
-            assert(m_value.object != nullptr);
-            return m_value.object->operator[](key);
-        }
-        else
-        {
-            throw std::domain_error("cannot use operator[] with " + type_name());
-        }
     }
 
     /*!
@@ -3134,7 +3119,89 @@ class basic_json
     @since version 1.0.0
     */
     template<typename T, std::size_t n>
-    const_reference operator[](const T (&key)[n]) const
+    const_reference operator[](T * (&key)[n]) const
+    {
+        return operator[](static_cast<const T>(key));
+    }
+
+    /*!
+    @brief access specified object element
+
+    Returns a reference to the element at with specified key @a key.
+
+    @note If @a key is not found in the object, then it is silently added to
+    the object and filled with a `null` value to make `key` a valid reference.
+    In case the value was `null` before, it is converted to an object.
+
+    @param[in] key  key of the element to access
+
+    @return reference to the element at key @a key
+
+    @throw std::domain_error if JSON is not an object or null; example:
+    `"cannot use operator[] with null"`
+
+    @complexity Logarithmic in the size of the container.
+
+    @liveexample{The example below shows how object elements can be read and
+    written using the [] operator.,operatorarray__key_type}
+
+    @sa @ref at(const typename object_t::key_type&) for access by reference
+    with range checking
+    @sa @ref value() for access by value with a default value
+
+    @since version 1.0.1
+    */
+    template<typename T>
+    reference operator[](T* key)
+    {
+        // implicitly convert null to object
+        if (is_null())
+        {
+            m_type = value_t::object;
+            m_value = value_t::object;
+        }
+
+        // at only works for objects
+        if (is_object())
+        {
+            assert(m_value.object != nullptr);
+            return m_value.object->operator[](key);
+        }
+        else
+        {
+            throw std::domain_error("cannot use operator[] with " + type_name());
+        }
+    }
+
+    /*!
+    @brief read-only access specified object element
+
+    Returns a const reference to the element at with specified key @a key. No
+    bounds checking is performed.
+
+    @warning If the element with key @a key does not exist, the behavior is
+    undefined.
+
+    @param[in] key  key of the element to access
+
+    @return const reference to the element at key @a key
+
+    @throw std::domain_error if JSON is not an object; example: `"cannot use
+    operator[] with null"`
+
+    @complexity Logarithmic in the size of the container.
+
+    @liveexample{The example below shows how object elements can be read using
+    the [] operator.,operatorarray__key_type_const}
+
+    @sa @ref at(const typename object_t::key_type&) for access by reference
+    with range checking
+    @sa @ref value() for access by value with a default value
+
+    @since version 1.0.1
+    */
+    template<typename T>
+    const_reference operator[](T* key) const
     {
         // at only works for objects
         if (is_object())
@@ -4785,7 +4852,7 @@ class basic_json
                 }
                 case value_t::number_float:
                 {
-                    return approx(lhs.m_value.number_float, rhs.m_value.number_float);
+                    return lhs.m_value.number_float == rhs.m_value.number_float;
                 }
                 default:
                 {
@@ -4795,13 +4862,11 @@ class basic_json
         }
         else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float)
         {
-            return approx(static_cast<number_float_t>(lhs.m_value.number_integer),
+            return static_cast<number_float_t>(lhs.m_value.number_integer == rhs.m_value.number_float);
-                          rhs.m_value.number_float);
         }
         else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer)
         {
-            return approx(lhs.m_value.number_float,
+            return lhs.m_value.number_float == static_cast<number_float_t>(rhs.m_value.number_integer);
-                          static_cast<number_float_t>(rhs.m_value.number_integer));
         }
         return false;
     }
@@ -7622,7 +7687,7 @@ basic_json_parser_64:
 
                     // check if conversion loses precision (special case -0.0 always loses precision)
                     const auto int_val = static_cast<number_integer_t>(result.m_value.number_float);
-                    if (approx(result.m_value.number_float, static_cast<number_float_t>(int_val)) &&
+                    if (result.m_value.number_float == static_cast<number_float_t>(int_val) &&
                         result.m_value.number_integer != json_value(-0.0f).number_integer)
                     {
                         // we would not lose precision -> return int
@@ -7767,4 +7832,9 @@ inline nlohmann::json operator "" _json(const char* s, std::size_t)
     return nlohmann::json::parse(reinterpret_cast<const nlohmann::json::string_t::value_type*>(s));
 }
 
+// restore GCC/clang diagnostic settings
+#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
+    #pragma GCC diagnostic pop
+#endif
+
 #endif

src/json.hpp.re2c

@@ -43,7 +43,9 @@ Class @ref nlohmann::basic_json is a good entry point for the documentation.
 #include <cassert>
 #include <ciso646>
 #include <cmath>
+#include <cstddef>
 #include <cstdio>
+#include <cstdlib>
 #include <functional>
 #include <initializer_list>
 #include <iomanip>
@@ -53,6 +55,7 @@ Class @ref nlohmann::basic_json is a good entry point for the documentation.
 #include <map>
 #include <memory>
 #include <sstream>
+#include <stdexcept>
 #include <string>
 #include <type_traits>
 #include <utility>
@@ -65,6 +68,12 @@ Class @ref nlohmann::basic_json is a good entry point for the documentation.
     #endif
 #endif
 
+// disable float-equal warnings on GCC/clang
+#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
+    #pragma GCC diagnostic push
+    #pragma GCC diagnostic ignored "-Wfloat-equal"
+#endif
+
 // enable ssize_t for MSVC
 #ifdef _MSC_VER
     #include <basetsd.h>
@@ -100,12 +109,6 @@ struct has_mapped_type
     static constexpr bool value = sizeof(test<T>(0)) == 1;
 };
 
-/// "equality" comparison for floating point numbers
-template<typename T>
-static bool approx(const T a, const T b)
-{
-    return not (a > b or a < b);
-}
 }
 
 /*!
@@ -2671,14 +2674,14 @@ class basic_json
 
     @since version 1.0.0
     */
-    template<typename ValueType, typename
+    template < typename ValueType, typename
-             std::enable_if<
+               std::enable_if <
-                 not std::is_pointer<ValueType>::value
+                   not std::is_pointer<ValueType>::value
-                 and not std::is_same<ValueType, typename string_t::value_type>::value
+                   and not std::is_same<ValueType, typename string_t::value_type>::value
 #ifndef _MSC_VER  // Fix for issue #167 operator<< abiguity under VS2015
-                 and not std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>::value
+                   and not std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>::value
 #endif
-                 , int>::type = 0>
+                   , int >::type = 0 >
     operator ValueType() const
     {
         // delegate the call to get<>() const
@@ -3062,8 +3065,6 @@ class basic_json
     the object and filled with a `null` value to make `key` a valid reference.
     In case the value was `null` before, it is converted to an object.
 
-    @note This function is required for compatibility reasons with Clang.
-
     @param[in] key  key of the element to access
 
     @return reference to the element at key @a key
@@ -3083,25 +3084,9 @@ class basic_json
     @since version 1.0.0
     */
     template<typename T, std::size_t n>
-    reference operator[](const T (&key)[n])
+    reference operator[](T * (&key)[n])
     {
-        // implicitly convert null to object
+        return operator[](static_cast<const T>(key));
-        if (is_null())
-        {
-            m_type = value_t::object;
-            m_value = value_t::object;
-        }
-
-        // at only works for objects
-        if (is_object())
-        {
-            assert(m_value.object != nullptr);
-            return m_value.object->operator[](key);
-        }
-        else
-        {
-            throw std::domain_error("cannot use operator[] with " + type_name());
-        }
     }
 
     /*!
@@ -3134,7 +3119,89 @@ class basic_json
     @since version 1.0.0
     */
     template<typename T, std::size_t n>
-    const_reference operator[](const T (&key)[n]) const
+    const_reference operator[](T * (&key)[n]) const
+    {
+        return operator[](static_cast<const T>(key));
+    }
+
+    /*!
+    @brief access specified object element
+
+    Returns a reference to the element at with specified key @a key.
+
+    @note If @a key is not found in the object, then it is silently added to
+    the object and filled with a `null` value to make `key` a valid reference.
+    In case the value was `null` before, it is converted to an object.
+
+    @param[in] key  key of the element to access
+
+    @return reference to the element at key @a key
+
+    @throw std::domain_error if JSON is not an object or null; example:
+    `"cannot use operator[] with null"`
+
+    @complexity Logarithmic in the size of the container.
+
+    @liveexample{The example below shows how object elements can be read and
+    written using the [] operator.,operatorarray__key_type}
+
+    @sa @ref at(const typename object_t::key_type&) for access by reference
+    with range checking
+    @sa @ref value() for access by value with a default value
+
+    @since version 1.0.1
+    */
+    template<typename T>
+    reference operator[](T* key)
+    {
+        // implicitly convert null to object
+        if (is_null())
+        {
+            m_type = value_t::object;
+            m_value = value_t::object;
+        }
+
+        // at only works for objects
+        if (is_object())
+        {
+            assert(m_value.object != nullptr);
+            return m_value.object->operator[](key);
+        }
+        else
+        {
+            throw std::domain_error("cannot use operator[] with " + type_name());
+        }
+    }
+
+    /*!
+    @brief read-only access specified object element
+
+    Returns a const reference to the element at with specified key @a key. No
+    bounds checking is performed.
+
+    @warning If the element with key @a key does not exist, the behavior is
+    undefined.
+
+    @param[in] key  key of the element to access
+
+    @return const reference to the element at key @a key
+
+    @throw std::domain_error if JSON is not an object; example: `"cannot use
+    operator[] with null"`
+
+    @complexity Logarithmic in the size of the container.
+
+    @liveexample{The example below shows how object elements can be read using
+    the [] operator.,operatorarray__key_type_const}
+
+    @sa @ref at(const typename object_t::key_type&) for access by reference
+    with range checking
+    @sa @ref value() for access by value with a default value
+
+    @since version 1.0.1
+    */
+    template<typename T>
+    const_reference operator[](T* key) const
     {
         // at only works for objects
         if (is_object())
@@ -4785,7 +4852,7 @@ class basic_json
                 }
                 case value_t::number_float:
                 {
-                    return approx(lhs.m_value.number_float, rhs.m_value.number_float);
+                    return lhs.m_value.number_float == rhs.m_value.number_float;
                 }
                 default:
                 {
@@ -4795,13 +4862,11 @@ class basic_json
         }
         else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float)
         {
-            return approx(static_cast<number_float_t>(lhs.m_value.number_integer),
+            return static_cast<number_float_t>(lhs.m_value.number_integer == rhs.m_value.number_float);
-                          rhs.m_value.number_float);
         }
         else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer)
         {
-            return approx(lhs.m_value.number_float,
+            return lhs.m_value.number_float == static_cast<number_float_t>(rhs.m_value.number_integer);
-                          static_cast<number_float_t>(rhs.m_value.number_integer));
         }
         return false;
     }
@@ -7304,7 +7369,7 @@ class basic_json
 
                     // check if conversion loses precision (special case -0.0 always loses precision)
                     const auto int_val = static_cast<number_integer_t>(result.m_value.number_float);
-                    if (approx(result.m_value.number_float, static_cast<number_float_t>(int_val)) &&
+                    if (result.m_value.number_float == static_cast<number_float_t>(int_val) &&
                         result.m_value.number_integer != json_value(-0.0f).number_integer)
                     {
                         // we would not lose precision -> return int
@@ -7449,4 +7514,9 @@ inline nlohmann::json operator "" _json(const char* s, std::size_t)
     return nlohmann::json::parse(reinterpret_cast<const nlohmann::json::string_t::value_type*>(s));
 }
 
+// restore GCC/clang diagnostic settings
+#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
+    #pragma GCC diagnostic pop
+#endif
+
 #endif

test/unit.cpp

@@ -25,6 +25,11 @@
 #include "json.hpp"
 using nlohmann::json;
 
+// disable float-equal warnings on GCC/clang
+#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
+    #pragma GCC diagnostic ignored "-Wfloat-equal"
+#endif
+
 TEST_CASE("constructors")
 {
     SECTION("create an empty value with a given type")
@@ -11501,11 +11506,59 @@ TEST_CASE("regression tests")
         CHECK(s2 == "value");
     }
 
-    SECTION("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 #171 - Cannot index by key of type static constexpr const char*")
+    {
+        json j;
+
+        // Non-const access with key as "char []"
+        char array_key[] = "Key1";
+        CHECK_NOTHROW(j[array_key] = 1);
+        CHECK(j[array_key] == json(1));
+
+        // Non-const access with key as "const char[]"
+        const char const_array_key[] = "Key2";
+        CHECK_NOTHROW(j[const_array_key] = 2);
+        CHECK(j[const_array_key] == json(2));
+
+        // Non-const access with key as "char *"
+        char _ptr_key[] = "Key3";
+        char* ptr_key = &_ptr_key[0];
+        CHECK_NOTHROW(j[ptr_key] = 3);
+        CHECK(j[ptr_key] == json(3));
+
+        // Non-const access with key as "const char *"
+        const char* const_ptr_key = "Key4";
+        CHECK_NOTHROW(j[const_ptr_key] = 4);
+        CHECK(j[const_ptr_key] == json(4));
+
+        // Non-const access with key as "static constexpr const char *"
+        static constexpr const char* constexpr_ptr_key = "Key5";
+        CHECK_NOTHROW(j[constexpr_ptr_key] = 5);
+        CHECK(j[constexpr_ptr_key] == json(5));
+
+        const json j_const = j;
+
+        // Const access with key as "char []"
+        CHECK(j_const[array_key] == json(1));
+
+        // Const access with key as "const char[]"
+        CHECK(j_const[const_array_key] == json(2));
+
+        //Const access with key as "char *"
+        CHECK(j_const[ptr_key] == json(3));
+
+        // Const access with key as "const char *"
+        CHECK(j_const[const_ptr_key] == json(4));
+
+        // Const access with key as "static constexpr const char *"
+        CHECK(j_const[constexpr_ptr_key] == json(5));
+    }
+
     SECTION("issue #186 miloyip/nativejson-benchmark: floating-point parsing")
     {
         json j;
@@ -11520,7 +11573,7 @@ TEST_CASE("regression tests")
         CHECK(j.get<double>() == 0.99999999999999989);
 
         // Test fails under GCC/clang due to strtod() error (may originate in libstdc++
-        // but seems to have been fixed in the most current versions)
+        // but seems to have been fixed in the most current versions - just not on Travis)
 #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
         j = json::parse("1.00000000000000011102230246251565404236316680908203126");
         CHECK(j.get<double>() == 1.00000000000000022);