mirror of
https://github.com/golang/go
synced 2024-11-05 20:36:10 -07:00
e24977d231
The next CL will remove the -G flag, effectively hard-coding it to its current default (-G=3). Change-Id: Ib4743b529206928f9f1cca9fdb19989728327831 Reviewed-on: https://go-review.googlesource.com/c/go/+/388534 Reviewed-by: Keith Randall <khr@golang.org> Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
95 lines
2.9 KiB
Go
95 lines
2.9 KiB
Go
// 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))
|
|
// }
|
|
}
|