Using tsl::ordered_map

[arvidsson]

Hi!

I'm using Visual Studio C++ 2017 and I get the following error when I try to use tsl::ordered_map with basic_json:

'std::pair<Key,T>::second' uses undefined class 'nlohmann::basic_jsontsl::ordered_map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer'

[nlohmann]

Related to #485.

[nlohmann]

I failed to compile an example myself, but did not find the time to dig into it.

[Tessil]

It seems ObjectType can only be a class which takes std::less<StringType> as third class template parameter and an allocator as fourth. See this using object_t line.

Also tsl::ordered_map needs an allocator with std::pair<Key, T> as value_type and not std::pair<const Key, T>.

One way to overcome these issues could be to use something like:

template<class Key, class T, class Ignore, class Allocator,
         class Hash = std::hash<Key>, class KeyEqual = std::equal_to<Key>,
         class AllocatorPair = typename std::allocator_traits<Allocator>::template rebind_alloc<std::pair<Key, T>>,
         class ValueTypeContainer = std::vector<std::pair<Key, T>, AllocatorPair>>
using ordered_map = tsl::ordered_map<Key, T, Hash, KeyEqual, AllocatorPair, ValueTypeContainer>;

using json = nlohmann::basic_json<ordered_map>;

But it's probably not the best solution.

The best solution would be to be able to use any associative container no matter where the position of the Allocator class parameter is, but I don't know how we could do that properly.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.