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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
commit | 43a123c1ae6613b3efeed291fa552ecd909d3acf (patch) | |
tree | fd92518b7024bc74031f78a1cf9e454b65e73665 /test/typeparam/absdiff.go | |
parent | Initial commit. (diff) | |
download | golang-1.20-upstream.tar.xz golang-1.20-upstream.zip |
Adding upstream version 1.20.14.upstream/1.20.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'test/typeparam/absdiff.go')
-rw-r--r-- | test/typeparam/absdiff.go | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/test/typeparam/absdiff.go b/test/typeparam/absdiff.go new file mode 100644 index 0000000..9c83eff --- /dev/null +++ b/test/typeparam/absdiff.go @@ -0,0 +1,94 @@ +// run + +// Copyright 2020 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package main + +type Numeric interface { + ~int | ~int8 | ~int16 | ~int32 | ~int64 | + ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr | + ~float32 | ~float64 | + ~complex64 | ~complex128 +} + +// numericAbs matches numeric types with an Abs method. +type numericAbs[T any] interface { + Numeric + Abs() T +} + +// AbsDifference computes the absolute value of the difference of +// a and b, where the absolute value is determined by the Abs method. +func absDifference[T numericAbs[T]](a, b T) T { + d := a - b + return d.Abs() +} + +// orderedNumeric matches numeric types that support the < operator. +type orderedNumeric interface { + ~int | ~int8 | ~int16 | ~int32 | ~int64 | + ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr | + ~float32 | ~float64 +} + +// Complex matches the two complex types, which do not have a < operator. +type Complex interface { + ~complex64 | ~complex128 +} + +// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639). +// // orderedAbs is a helper type that defines an Abs method for +// // ordered numeric types. +// type orderedAbs[T orderedNumeric] T +// +// func (a orderedAbs[T]) Abs() orderedAbs[T] { +// if a < 0 { +// return -a +// } +// return a +// } +// +// // complexAbs is a helper type that defines an Abs method for +// // complex types. +// type complexAbs[T Complex] T +// +// func (a complexAbs[T]) Abs() complexAbs[T] { +// r := float64(real(a)) +// i := float64(imag(a)) +// d := math.Sqrt(r*r + i*i) +// return complexAbs[T](complex(d, 0)) +// } +// +// // OrderedAbsDifference returns the absolute value of the difference +// // between a and b, where a and b are of an ordered type. +// func orderedAbsDifference[T orderedNumeric](a, b T) T { +// return T(absDifference(orderedAbs[T](a), orderedAbs[T](b))) +// } +// +// // ComplexAbsDifference returns the absolute value of the difference +// // between a and b, where a and b are of a complex type. +// func complexAbsDifference[T Complex](a, b T) T { +// return T(absDifference(complexAbs[T](a), complexAbs[T](b))) +// } + +func main() { + // // For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639). + // if got, want := orderedAbsDifference(1.0, -2.0), 3.0; got != want { + // panic(fmt.Sprintf("got = %v, want = %v", got, want)) + // } + // if got, want := orderedAbsDifference(-1.0, 2.0), 3.0; got != want { + // panic(fmt.Sprintf("got = %v, want = %v", got, want)) + // } + // if got, want := orderedAbsDifference(-20, 15), 35; got != want { + // panic(fmt.Sprintf("got = %v, want = %v", got, want)) + // } + // + // if got, want := complexAbsDifference(5.0+2.0i, 2.0-2.0i), 5+0i; got != want { + // panic(fmt.Sprintf("got = %v, want = %v", got, want)) + // } + // if got, want := complexAbsDifference(2.0-2.0i, 5.0+2.0i), 5+0i; got != want { + // panic(fmt.Sprintf("got = %v, want = %v", got, want)) + // } +} |