Simple voting contract

voting.cpp

#include <eosiolib/eosio.hpp>

namespace eosio {
  class voting : public eosio::contract {
    /// @abi table candidates i64
    struct candidate {
      uint64_t id;
      account_name name;

      auto primary_key() const { return id; }
    };

    public:
      voting(account_name self): contract(self) {}
      typedef eosio::multi_index<N(candidates), candidate> Candidates;

      /// @abi action
      void acandidate( account_name name ) {
        Candidates candidates( _self, _self);
        candidates.emplace( _self, [&]( auto& user ) {
          user.id = candidates.available_primary_key();
          user.name = name;
        });
      }

      /// @abi action
      void ucandidate( uint64_t id, account_name name ) {
        Candidates candidates( _self, _self );
        auto itr = candidates.find( id );
        eosio_assert(itr != candidates.end(), "No candidate found with this id.");
        candidates.modify( itr, _self, [&]( auto& user ) {
          user.name = name;
        });
      }

      /// @abi action
      void dcandidate( uint64_t id ) {
        Candidates candidates( _self, _self );
        auto itr = candidates.find( id );
        eosio_assert(itr != candidates.end(), "No candidate found with this id.");
        candidates.erase( itr );
        eosio_assert(itr != candidates.end(), "Candidate not erased properly.");
      }

      /// @abi action
      void debug( uint64_t id ) {
        print("Hello, ", name{gcandidate(id)});
      }

      /// @abi action
      account_name gcandidate( uint64_t id ) const {
        Candidates candidates( _self, _self );
        auto itr = candidates.find( id );
        eosio_assert(itr != candidates.end(), "No candidate found with this id.");
        return itr->name;
      }
  };
} /// namespace eosio

EOSIO_ABI( eosio::voting, (acandidate)(ucandidate)(dcandidate)(debug) )