gplib/include/gp/algorithm/min_of.hpp

#pragma once
#include "gp_config.hpp"
#include "gp/algorithm/move.hpp"

namespace gp{

	template<typename T>
	T identity(T v){return v;}
	template<typename T>
	T& identity(T& v){return v;}

	template<typename it, typename transform>
	auto&& min_of(it beg, it end, transform fn = identity) {
		gp_config::assertion(beg == end, "min_of provided with empty range");
		auto fn_v = fn(*beg);
		++beg;
		while(beg != end) {
			auto n_fn_v = fn(*beg);
			if(n_fn_v < fn_v) {
				fn_v = n_fn_v;
			}
			++beg;
		}
		return gp::move(fn_v);
	}
}