gistfile1.cpp

//#include "opencv_traits.hh"

#include <opencv2/core/core.hpp>

#include <set>
#include <tuple>
#include <map>
#include <vector>

template <typename value_t>
struct Value_ {
	value_t value = 0;
	Value_() {}
	Value_(value_t v): value(v) {}
};


typedef Value_<int> Value;

bool operator < (const Value &u, const Value &v) {
	return u.value < v.value;
}


bool operator < (const cv::Vec3b &a, const cv::Vec3b &b) {
	return std::tie(a[0], a[1], a[2]) < std::tie(b[0], b[1], b[2]);
}

int main () {
//    std::map<cv::Vec3b, int> s;
//    s[cv::Vec3b(0, 255, 0)] = 1; // <-- won't compile

	std::map<Value, int> sv;
	sv[Value(1)] = 1; // <-- but this will do

	return 0;
}