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get(): It is used to access the tuple values and modify them, it accepts the index and tuple name as arguments to access a particular tuple element. What is map? Maps in C++ are associative containers that can store elements in a mapped fashion. Each element of a map has a key and the corresponding mapped value.
The answer is no, can't be done for all tuples, since a tuple is a variadic template type.
An unordered set of tuples is an unordered set in which each of the elements is a tuple. Note that by default an unordered set doesn't have the functionality of tuples. In simple words, one cannot declare an unordered set of tuples directly in C++. One have to pass a Hash function as an argument to the unordered set.
Because unordered_map containers do not allow for duplicate keys, this means that the function actually returns 1 if an element with that key exists in the container, and zero otherwise.
I want to use tuple consisting of int,char,char in my unordered_map. I am doing like this:
#include <string> #include <unordered_map> #include <cstring> #include <iostream> #include <tuple> using namespace std; tuple <int,char,char> kk; unordered_map<kk,int> map; int main() { map[1,"c","b"]=23; return 0; } but this gives me following errors:
map.cpp:9:21: error: type/value mismatch at argument 1 in template parameter list for ‘template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> class std::unordered_map’ map.cpp:9:21: error: expected a type, got ‘kk’ map.cpp:9:21: error: template argument 3 is invalid map.cpp:9:21: error: template argument 4 is invalid map.cpp:9:21: error: template argument 5 is invalid map.cpp:9:26: error: invalid type in declaration before ‘;’ token map.cpp: In function ‘int main()’: map.cpp:14:16: error: assignment of read-only location ‘"b"[map]’ What I am doing wrong in this?
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