From 92bbdcdd9725cd5a4633e7fc44d33420d5764b08 Mon Sep 17 00:00:00 2001
From: Dan Kortschak <dan@kortschak.io>
Date: Thu, 10 Mar 2022 22:56:08 +1030
Subject: [PATCH] spatial/r3: use array conversion in safe code

---
 go.mod                   | 2 +-
 spatial/r3/mat_safe.go   | 8 +-------
 spatial/r3/mat_unsafe.go | 1 -
 3 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/go.mod b/go.mod
index cfb5fca9..ee321a26 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module gonum.org/v1/gonum
 
-go 1.14
+go 1.17
 
 require (
 	github.com/google/go-cmp v0.5.7
diff --git a/spatial/r3/mat_safe.go b/spatial/r3/mat_safe.go
index 89a3250b..740259c1 100644
--- a/spatial/r3/mat_safe.go
+++ b/spatial/r3/mat_safe.go
@@ -127,14 +127,8 @@ func (m *Mat) RawMatrix() blas64.General {
 	return blas64.General{Rows: 3, Cols: 3, Data: m.data[:], Stride: 3}
 }
 
-// BUG(kortschak): Implementing NewMat without unsafe conversion or slice to
-// array pointer conversion leaves it with semantics that do not match the
-// sharing semantics that exist in the mat package.
 func arrayFrom(vals []float64) *array {
-	// TODO(kortschak): Use array conversion when go1.16 is no longer supported.
-	var a array
-	copy(a[:], vals)
-	return &a
+	return (*array)(vals)
 }
 
 // Mat returns a 3×3 rotation matrix corresponding to the receiver. It
diff --git a/spatial/r3/mat_unsafe.go b/spatial/r3/mat_unsafe.go
index 63b6e6bb..c6c6d4f3 100644
--- a/spatial/r3/mat_unsafe.go
+++ b/spatial/r3/mat_unsafe.go
@@ -140,7 +140,6 @@ func (r Rotation) Mat() *Mat {
 }
 
 func arrayFrom(vals []float64) *array {
-	// TODO(kortschak): Use array conversion when go1.16 is no longer supported.
 	return (*array)(unsafe.Pointer(&vals[0]))
 }