From 1dd3905d146f13c4c5a1c3aa7132ebc7f7342366 Mon Sep 17 00:00:00 2001
From: Jiri Pittner <jiri@pittnerovi.com>
Date: Fri, 17 Oct 2025 14:07:47 +0200
Subject: [PATCH] trivial subvector of full size return *this

---
 vec.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/vec.cc b/vec.cc
index dc16611..c4434cb 100644
--- a/vec.cc
+++ b/vec.cc
@@ -877,6 +877,9 @@ const NRVec<T> NRVec<T>::subvector(const int from, const int to) const
 		laerror("invalid subvector specification");
 	}
 #endif
+//trivial case of whole vector for efficiency
+	if(from==0 && to == nn-1) return *this;
+
 	const int n = to - from + 1;
 	NRVec<T> r(n, getlocation());
 	if(!LA_traits<T>::is_plaindata()) laerror("only implemented for plain data");