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// Copyright ©2015 The Gonum Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !appengine,!safe
package mat
import "unsafe"
// offset returns the number of float64 values b[0] is after a[0].
func offset(a, b []float64) int {
if &a[0] == &b[0] {
return 0
}
// This expression must be atomic with respect to GC moves.
// At this stage this is true, because the GC does not
// move. See https://golang.org/issue/12445.
return int(uintptr(unsafe.Pointer(&b[0]))-uintptr(unsafe.Pointer(&a[0]))) / int(unsafe.Sizeof(float64(0)))
}
// offsetComplex returns the number of complex128 values b[0] is after a[0].
func offsetComplex(a, b []complex128) int {
if &a[0] == &b[0] {
return 0
}
// This expression must be atomic with respect to GC moves.
// At this stage this is true, because the GC does not
// move. See https://golang.org/issue/12445.
return int(uintptr(unsafe.Pointer(&b[0]))-uintptr(unsafe.Pointer(&a[0]))) / int(unsafe.Sizeof(complex128(0)))
}
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