Why cant I insert a struct value in an unordered

I have created a very simple example to show the problem:

#include <unordered_map>

int main() {
    struct Example {
        int num;
        float decimal;
    };

    std::unordered_map<int, Example> map;
    map.insert(1, { 2, 3.4 }); // Error none of the overloads match!
}

I should be able to insert into the map of int and struct Example but the compiler says none of the overloads match..?

CodePudding user response：

The reason for the error message is, that none of the overloads of std::unordered_map::insert takes a key and a value parameter.

You should do

map.insert({1, { 2, 3.4 }});

instead of

map.insert(1, { 2, 3.4 });

You may refer to the 6th overload of std::unordered_map::insert at https://en.cppreference.com/w/cpp/container/unordered_map/insert