tartg / uebungen_prgt_1718 Goto Github PK

Hello,
I'm having the problem to properly compile the code and receive the following error:

error: no match for call to '(const std::hash) (const EventType&)'

build with TDM-GCC-64 (x86_64-w64-mingw32) also tried with the normal mingw32 but still that error.

Made a minimalistic example of it:

#include <iostream>
#include <unordered_map>

enum class test{
	A,B,C,D,E,F
};

int main() {
	std::cout << "!!!Hello World!!!" << std::endl;
	std::unordered_map<test,int, std::hash<int> > m;
	m[test::A] = 12;

	std::cout << "m[test::A]:" << m[test::A] << std::endl;
	return 0;
}

and it still produces that error. I suspect that is has to do with the strong type of the enum class which does not have an implicit conversion to int. But unordered_map needs int for the hash function. unordered_map just knows about int and not about test or EventType (in this case).

also see:
https://stackoverflow.com/questions/8357240/how-to-automatically-convert-strongly-typed-enum-into-int
https://stackoverflow.com/questions/18837857/cant-use-enum-class-as-unordered-map-key