Error with as<char*>()

From @sammys:

Arduino: 1.6.8 (Mac OS X), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

In file included from ../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.hpp:153:0,
                 > from ../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonArray.ipp:11,
                 > from ../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonArray.hpp:181,
                 > from ../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson.h:9,
                 > from ../Arduino/libraries/ArduinoJson/src/ArduinoJson.h:14,
                 > from sketch/config.cpp:4:
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp: In instantiation of 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15: error: no matching function for call to 'ArduinoJson::JsonVariant::as()'
return node ? node->content.value.as<T>() : JsonVariant::invalid<T>();
               > ^
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15: note: candidates are:
In file included from JsonBuffer.hpp:15:0,
                 > from ../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/Internals/BlockJsonBuffer.hpp:10,
                 > from ../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/DynamicJsonBuffer.hpp:10,
                 > from ../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson.h:8,
                 > from ../Arduino/libraries/ArduinoJson/src/ArduinoJson.h:14,
                 > from sketch/config.cpp:4:
JsonVariant.hpp:97:3: note: template<class T> const typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsIntegral<T>::value, T>::type ArduinoJson::JsonVariant::as() const
as() const {
^
JsonVariant.hpp:97:3: note:   template argument deduction/substitution failed:
JsonVariant.hpp: In substitution of 'template<class T> const typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsIntegral<T>::value, T>::type ArduinoJson::JsonVariant::as() const > [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15:   required from 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:97:3: error: no type named 'type' in 'struct ArduinoJson::TypeTraits::EnableIf<false, char*>'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp: In instantiation of 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:105:3: note: template<class T> const typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsFloatingPoint<T>::value, T>::type ArduinoJson::JsonVariant::as() const
as() const {
^
JsonVariant.hpp:105:3: note:   template argument deduction/substitution failed:
JsonVariant.hpp: In substitution of 'template<class T> const typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsFloatingPoint<T>::value, T>::type ArduinoJson::JsonVariant::as() > const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15:   required from 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:105:3: error: no type named 'type' in 'struct ArduinoJson::TypeTraits::EnableIf<false, char*>'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp: In instantiation of 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:112:3: note: template<class T> const typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<T, String>::value, T>::type ArduinoJson::JsonVariant::as() const
as() const {
^
JsonVariant.hpp:112:3: note:   template argument deduction/substitution failed:
JsonVariant.hpp: In substitution of 'template<class T> const typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<T, String>::value, T>::type ArduinoJson::JsonVariant::as() > const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15:   required from 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:112:3: error: no type named 'type' in 'struct ArduinoJson::TypeTraits::EnableIf<false, char*>'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp: In instantiation of 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:120:3: note: template<class T> typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<T, const char*>::value, const char*>::type ArduinoJson::JsonVariant::as() > const
as() const {
^
JsonVariant.hpp:120:3: note:   template argument deduction/substitution failed:
JsonVariant.hpp: In substitution of 'template<class T> typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<T, const char*>::value, const char*>::type > ArduinoJson::JsonVariant::as() const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15:   required from 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:120:3: error: no type named 'type' in 'struct ArduinoJson::TypeTraits::EnableIf<false, const char*>'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp: In instantiation of 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:127:3: note: template<class T> const typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<T, bool>::value, T>::type ArduinoJson::JsonVariant::as() const
as() const {
^
JsonVariant.hpp:127:3: note:   template argument deduction/substitution failed:
JsonVariant.hpp: In substitution of 'template<class T> const typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<T, bool>::value, T>::type ArduinoJson::JsonVariant::as() > const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15:   required from 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:127:3: error: no type named 'type' in 'struct ArduinoJson::TypeTraits::EnableIf<false, char*>'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp: In instantiation of 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:140:3: note: template<class T> typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<typename ArduinoJson::TypeTraits::RemoveConst<typename > ArduinoJson::TypeTraits::RemoveReference<T>::type>::type, ArduinoJson::JsonArray>::value, ArduinoJson::JsonArray&>::type ArduinoJson::JsonVariant::as() const
as() const {
^
JsonVariant.hpp:140:3: note:   template argument deduction/substitution failed:
JsonVariant.hpp: In substitution of 'template<class T> typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<typename ArduinoJson::TypeTraits::RemoveConst<typename > ArduinoJson::TypeTraits::RemoveReference<T>::type>::type, ArduinoJson::JsonArray>::value, ArduinoJson::JsonArray&>::type ArduinoJson::JsonVariant::as() const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15:   required from 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:140:3: error: no type named 'type' in 'struct ArduinoJson::TypeTraits::EnableIf<false, ArduinoJson::JsonArray&>'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp: In instantiation of 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:153:3: note: template<class T> typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<typename ArduinoJson::TypeTraits::RemoveConst<typename > ArduinoJson::TypeTraits::RemoveReference<T>::type>::type, ArduinoJson::JsonObject>::value, ArduinoJson::JsonObject&>::type ArduinoJson::JsonVariant::as() const
as() const {
^
JsonVariant.hpp:153:3: note:   template argument deduction/substitution failed:
JsonVariant.hpp: In substitution of 'template<class T> typename ArduinoJson::TypeTraits::EnableIf<ArduinoJson::TypeTraits::IsSame<typename ArduinoJson::TypeTraits::RemoveConst<typename > ArduinoJson::TypeTraits::RemoveReference<T>::type>::type, ArduinoJson::JsonObject>::value, ArduinoJson::JsonObject&>::type ArduinoJson::JsonVariant::as() const [with T = char*]':
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObject.ipp:24:15:   required from 'T ArduinoJson::JsonObject::get(ArduinoJson::JsonObjectKey) const [with T = char*]'
../Arduino/libraries/ArduinoJson/src/../include/ArduinoJson/JsonObjectSubscript.hpp:54:36:   required from 'TValue ArduinoJson::JsonObjectSubscript<TKey>::as() const [with TValue = char*; TKey = > const char*]'
JsonVariantBase.hpp:45:35:   required from 'const T ArduinoJson::JsonVariantBase<TImpl>::as() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
JsonVariantBase.hpp:40:14:   required from 'ArduinoJson::JsonVariantBase<TImpl>::operator T() const [with T = char*; TImpl = ArduinoJson::JsonObjectSubscript<const char*>]'
sketch/config.cpp:13:14:   required from here
JsonVariant.hpp:153:3: error: no type named 'type' in 'struct ArduinoJson::TypeTraits::EnableIf<false, ArduinoJson::JsonObject&>'
exit status 1
Error compiling for board Arduino/Genuino Mega or Mega 2560.

I beleive that the faulty line is

root["something"].as<char*>()

instead of

root["something"].as<const char*>()