#include <iostream>
using namespace std;
 
enum Flavor { Cherry, Plum, Raspberry };
 
template <Flavor> using Number = double;
 
void printCherryNumber(Number<Cherry> num) { cout << num << endl; }
 
template <typename T> void printCherryNumber(T num) = delete;
 
// Doesn't work. "Cannot infer type argument F."
template <Flavor F>
void printPlumNumber(Number<F> num) {
	static_assert(F == Plum, "Wrong number flavor!");
	cout << num << endl;
}
 
// Doesn't work. Compiler rightly treats the call as ambiguous.
template <Flavor F> void printRaspberryNumber(Number<F> num) = delete;
 
template <> void printRaspberryNumber<Raspberry>(Number<Raspberry> num) {
	cout << num << endl;
}
 
int main() {
	Number<Cherry> a(5);
	Number<Plum> b(6);
	Number<Raspberry> c(3.1415);
 
	printCherryNumber(a);
	printCherryNumber(b);  // O, if only this could be a compiler error.
 
	return 0;
}

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