From da41b70b18d8e05bc4f5aba19df9aad511fa3d5a Mon Sep 17 00:00:00 2001
From: Zufu Liu <unknown>
Date: Wed, 8 Jan 2025 09:20:56 +1100
Subject: Feature [feature-requests:#1540]. Optimize InsertEmpty to memset
 equivalent. Simplify second argument by std::fill -> std::fill_n, std::copy
 -> std::copy_n.

---
 src/SplitVector.h | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

(limited to 'src')

diff --git a/src/SplitVector.h b/src/SplitVector.h
index 19b854f5a..081c7cbfb 100644
--- a/src/SplitVector.h
+++ b/src/SplitVector.h
@@ -191,7 +191,7 @@ public:
 			}
 			RoomFor(insertLength);
 			GapTo(position);
-			std::fill(body.data() + part1Length, body.data() + part1Length + insertLength, v);
+			std::fill_n(body.data() + part1Length, insertLength, v);
 			lengthBody += insertLength;
 			part1Length += insertLength;
 			gapLength -= insertLength;
@@ -210,10 +210,8 @@ public:
 			}
 			RoomFor(insertLength);
 			GapTo(position);
-			for (ptrdiff_t elem = part1Length; elem < part1Length + insertLength; elem++) {
-				T emptyOne = {};
-				body[elem] = std::move(emptyOne);
-			}
+			T *ptr = body.data() + part1Length;
+			std::uninitialized_value_construct_n(ptr, insertLength);
 			lengthBody += insertLength;
 			part1Length += insertLength;
 			gapLength -= insertLength;
@@ -238,7 +236,7 @@ public:
 			}
 			RoomFor(insertLength);
 			GapTo(positionToInsert);
-			std::copy(s + positionFrom, s + positionFrom + insertLength, body.data() + part1Length);
+			std::copy_n(s + positionFrom, insertLength, body.data() + part1Length);
 			lengthBody += insertLength;
 			part1Length += insertLength;
 			gapLength -= insertLength;
@@ -284,11 +282,11 @@ public:
 			if (range1Length > part1AfterPosition)
 				range1Length = part1AfterPosition;
 		}
-		std::copy(body.data() + position, body.data() + position + range1Length, buffer);
+		std::copy_n(body.data() + position, range1Length, buffer);
 		buffer += range1Length;
 		position = position + range1Length + gapLength;
 		const ptrdiff_t range2Length = retrieveLength - range1Length;
-		std::copy(body.data() + position, body.data() + position + range2Length, buffer);
+		std::copy_n(body.data() + position, range2Length, buffer);
 	}
 
 	/// Compact the buffer and return a pointer to the first element.
-- 
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