From 2323bd7452339eb57d6ac7fe494ed1ae7d11d567 Mon Sep 17 00:00:00 2001
From: Eduard Valeyev <eduard@valeyev.net>
Date: Thu, 26 Sep 2024 09:22:35 -0400
Subject: [PATCH] make sure to initialize unused metadata data in
 constexpr-rank arrays

---
 btas/array_adaptor.h   | 2 ++
 unittest/range_test.cc | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/btas/array_adaptor.h b/btas/array_adaptor.h
index fc8bac2b..fb314e0d 100644
--- a/btas/array_adaptor.h
+++ b/btas/array_adaptor.h
@@ -32,6 +32,8 @@ namespace btas {
       static array construct(std::size_t n) {
         assert(n <= N);
         array result;
+        // fill elements n+1 ... N-1 with zeroes
+        std::fill_n(result.begin() + n, N - n, value_type{});
         return result;
       }
       static array construct(std::size_t n, T value) {
diff --git a/unittest/range_test.cc b/unittest/range_test.cc
index b95b6619..c48f9f33 100644
--- a/unittest/range_test.cc
+++ b/unittest/range_test.cc
@@ -70,6 +70,10 @@ TEST_CASE("Range")
         typedef RangeNd<blas::Layout::RowMajor, std::array<size_t, 3>> Range3d;
         Range3d x;
         CHECK(x.rank()== 3);
+        CHECK(x.area()== 0);
+        Range3d x1(std::array<int,0>{},std::array<int,0>{});
+        CHECK(x1.rank()== 3);
+        CHECK(x1.area()== 0);
         }
     SECTION("Col-major std::vector-based Range")
         {