#pragma once

#include <functional>
#include <cassert>

namespace wrp{ namespace math{

	template<size_t B, typename T>
	inline const T max_power_of(const T n)
	{
		assert(B > 1);
		assert(n > 0);

		std::function<const T(const T)> f_ = [&](const T c)->const T
		{
			const T cb = c * (const T)B;
			return cb > n ? c : f_(cb);
		};

		return f_(1);
	}


	namespace tmp{

		template<size_t N>
		struct max_power_of_2
		{
		private:
			template<size_t N, size_t C, size_t R>
			struct f_
			{
			private:
				static const size_t c2 = C << 1;
			public:
				static const size_t result = f_<N, c2, N / c2>::result;
			};

			template<size_t N, size_t C>
			struct f_<N, C, 1>
			{
				static const size_t result = C;
			};

		public:
			static const size_t result = f_<N, 1, N>::result;
		};
	}


}}