add built-in array support in get_to

include/nlohmann/detail/conversions/from_json.hpp

@@ -157,6 +157,16 @@ void from_json(const BasicJsonType& j, std::valarray<T>& l)
     std::copy(j.m_value.array->begin(), j.m_value.array->end(), std::begin(l));
 }
 
+template <typename BasicJsonType, typename T, std::size_t N>
+auto from_json(const BasicJsonType& j, T (&arr)[N])
+-> decltype(j.template get<T>(), void())
+{
+    for (std::size_t i = 0; i < N; ++i)
+    {
+        arr[i] = j.at(i).template get<T>();
+    }
+}
+
 template<typename BasicJsonType>
 void from_json_array_impl(const BasicJsonType& j, typename BasicJsonType::array_t& arr, priority_tag<3> /*unused*/)
 {

include/nlohmann/json.hpp

@@ -2684,6 +2684,19 @@ class basic_json
         return v;
     }
 
+    template <
+        typename T, std::size_t N,
+        typename Array = T (&)[N],
+        detail::enable_if_t <
+            detail::has_from_json<basic_json_t, Array>::value, int > = 0 >
+    Array get_to(T (&v)[N]) const
+    noexcept(noexcept(JSONSerializer<Array>::from_json(
+                          std::declval<const basic_json_t&>(), v)))
+    {
+        JSONSerializer<Array>::from_json(*this, v);
+        return v;
+    }
+
 
     /*!
     @brief get a pointer value (implicit)

single_include/nlohmann/json.hpp

@@ -1445,6 +1445,16 @@ void from_json(const BasicJsonType& j, std::valarray<T>& l)
     std::copy(j.m_value.array->begin(), j.m_value.array->end(), std::begin(l));
 }
 
+template <typename BasicJsonType, typename T, std::size_t N>
+auto from_json(const BasicJsonType& j, T (&arr)[N])
+-> decltype(j.template get<T>(), void())
+{
+    for (std::size_t i = 0; i < N; ++i)
+    {
+        arr[i] = j.at(i).template get<T>();
+    }
+}
+
 template<typename BasicJsonType>
 void from_json_array_impl(const BasicJsonType& j, typename BasicJsonType::array_t& arr, priority_tag<3> /*unused*/)
 {
@@ -15475,6 +15485,19 @@ class basic_json
         return v;
     }
 
+    template <
+        typename T, std::size_t N,
+        typename Array = T (&)[N],
+        detail::enable_if_t <
+            detail::has_from_json<basic_json_t, Array>::value, int > = 0 >
+    Array get_to(T (&v)[N]) const
+    noexcept(noexcept(JSONSerializer<Array>::from_json(
+                          std::declval<const basic_json_t&>(), v)))
+    {
+        JSONSerializer<Array>::from_json(*this, v);
+        return v;
+    }
+
 
     /*!
     @brief get a pointer value (implicit)

test/src/unit-conversions.cpp

@@ -386,6 +386,16 @@ TEST_CASE("value conversion")
             CHECK(json(a) == j);
         }
 
+        SECTION("built-in arrays")
+        {
+            const int nbs[] = {0, 1, 2};
+            int nbs2[] = {0, 0, 0};
+
+            json j2 = nbs;
+            j2.get_to(nbs2);
+            CHECK(std::equal(std::begin(nbs), std::end(nbs), std::begin(nbs2)));
+        }
+
         SECTION("std::deque<json>")
         {
             std::deque<json> a{"previous", "value"};