Samples with eosio.cdt v1.3.0? multi_index with secondary indexes and get_index

Question

Has anyone been successful getting a contract which uses secondary indexes to compile against the latest versions of the CDT (1.3.2)?

I'm having trouble and don't see any updated samples which use index_by and get_index for a secondary index on a table.

Answer 1

Here is an example from the eosio.cdt Gitbook:

#include <eosiolib/eosio.hpp>
using namespace eosio;
class mycontract: contract {
  struct record {
    uint64_t    primary;
    uint64_t    secondary_1;
    uint128_t   secondary_2;
    checksum256 secondary_3;
    double      secondary_4;
    long double secondary_5;
    uint64_t primary_key() const { return primary; }
    uint64_t get_secondary_1() const { return secondary_1; }
    uint128_t get_secondary_2() const { return secondary_2; }
    checksum256 get_secondary_3() const { return secondary_3; }
    double get_secondary_4() const { return secondary_4; }
    long double get_secondary_5() const { return secondary_5; }
  };
  public:
    mycontract(name receiver, name code, datastream<const char*> ds):contract(receiver, code, ds){}
    void myaction() {
      auto code = _self;
      auto scope = _self;
      multi_index<"mytable"_n, record,
        indexed_by< "bysecondary1"_n, const_mem_fun<record, uint64_t, &record::get_secondary_1> >,
        indexed_by< "bysecondary2"_n, const_mem_fun<record, uint128_t, &record::get_secondary_2> >,
        indexed_by< "bysecondary3"_n, const_mem_fun<record, checksum256, &record::get_secondary_3> >,
        indexed_by< "bysecondary4"_n, const_mem_fun<record, double, &record::get_secondary_4> >,
        indexed_by< "bysecondary5"_n, const_mem_fun<record, long double, &record::get_secondary_5> >
      > table( code, scope);
    }
}
EOSIO_DISPATCH( mycontract, (myaction) )

You then use the get_index function, described as:

Returns an appropriately typed Secondary Index.

Template parameters:

IndexName - the ID of the desired secondary index Returns:

An index of the appropriate type: Primitive 64-bit unsigned integer key (idx64), Primitive 128-bit unsigned integer key (idx128), 128-bit fixed-size lexicographical key (idx128), 256-bit fixed-size lexicographical key (idx256), Floating point key, Double precision floating point key, Long Double (quadruple) precision floating point key

Example:

#include <eosiolib/eosio.hpp>
using namespace eosio;
using namespace std;
class addressbook: contract {
  struct address {
     uint64_t account_name;
     string first_name;
     string last_name;
     string street;
     string city;
     string state;
     uint32_t zip = 0;
     uint64_t primary_key() const { return account_name; }
     uint64_t by_zip() const { return zip; }
  };
  public:
    addressbook(name receiver, name code, datastream<const char*> ds):contract(receiver, code, ds) {}
    typedef eosio::multi_index< name("address"), address, indexed_by< name("zip"), const_mem_fun<address, uint64_t, &address::by_zip> > address_index;
    void myaction() {
      // create reference to address_index  - see emplace example below
      // add dan account to table           - see emplace example below
      uint32_t zipnumb = 93446;
      auto zip_index = addresses.get_index<name("zip")>();      // <-- THIS IS THE LINE
      auto itr = zip_index.find(zipnumb);
      eosio::check(itr->account_name == name("dan"), "Lock arf, Incorrect Record ");
    }
}
EOSIO_DISPATCH( addressbook, (myaction) )