CODEWITHSUNDEEP
c++
Alberto Soto Ballesteros
Alberto Soto Ballesteros

Reputation: 170

No matching member function in Map insert

I have the following two variables:

static vector<map<uint32_t,vector<uint64_t>>> relations;
static map<uint64_t,map<uint32_t,vector<uint64_t>>> transactions;

uint64_t key1;
uint32_t key2;
uint32_t key3;
// init keys...

And I am trying to copy one vector from relations into transactions:

transactions[key1][key2].push_back(relations[key2][key3]));

But I find this error:

main.cpp:175:26: error: no matching member function for call to 'push_back'
     transactions[key1][key2].push_back(relations[key2][key3]));
     ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/vector:700:36: note: candidate function not viable: no
  known conversion from 'vector<uint64_t>' to 'const value_type' (aka 'const unsigned long long') for 1st argument
_LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
                               ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/vector:702:36: note: candidate function not viable: no
  known conversion from 'vector<uint64_t>' to 'value_type' (aka 'unsigned long long') for 1st argument
_LIBCPP_INLINE_VISIBILITY void push_back(value_type&& __x);

Any idea of what's happening?

Upvotes: 1

Views: 494

Answers (1)

flogram_dev
flogram_dev

Reputation: 42888

relations[key2][key3] is a vector<uint64_t>, and you're trying to add it to transactions[key1][key2] which is a vector<uint64_t>.

You can't add vector<uint64_t> to a vector<uint64_t>.

If you'd like to add the contents of the first vector to the second one, you need to use std::vector::insert:

auto& dst = transactions[key1][key2];
const auto& src = relations[key2][key3];
dst.insert(dst.end(), src.begin(), src.end());

Upvotes: 6

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