From 769b5786ae958a4aae772872d4cebeacd7fdbe1a Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Tue, 6 Jun 2023 13:21:39 +0300
Subject: [PATCH] Add util::array::subarray

---
 libs/util/include/psemek/util/array.hpp | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/libs/util/include/psemek/util/array.hpp b/libs/util/include/psemek/util/array.hpp
index 55fa74cd..2a804506 100644
--- a/libs/util/include/psemek/util/array.hpp
+++ b/libs/util/include/psemek/util/array.hpp
@@ -118,6 +118,7 @@ namespace psemek::util
 		T const & operator()(std::initializer_list<I> const & index) const;
 
 		array copy() const;
+		array subarray(dims_type const & start, dims_type const & end) const;
 
 		void resize(dims_type const & dims);
 
@@ -383,6 +384,25 @@ namespace psemek::util
 		return array{dims_, std::move(data)};
 	}
 
+	template <typename T, std::size_t N>
+	array<T, N> array<T, N>::subarray(dims_type const & start, dims_type const & end) const
+	{
+		dims_type size;
+		for (std::size_t i = 0; i < N; ++i)
+			size[i] = end[i] - start[i];
+
+		array<T, N> result(size);
+		for (auto const & idx : result.indices())
+		{
+			auto jdx = idx;
+			for (std::size_t i = 0; i < N; ++i)
+				jdx[i] += start[i];
+			result(idx) = (*this)(jdx);
+		}
+
+		return result;
+	}
+
 	template <typename T, std::size_t N>
 	void array<T, N>::resize(dims_type const & dims)
 	{