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Diffstat (limited to 'test/typeparam/absdiffimp.dir/a.go')
-rw-r--r-- | test/typeparam/absdiffimp.dir/a.go | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/test/typeparam/absdiffimp.dir/a.go b/test/typeparam/absdiffimp.dir/a.go new file mode 100644 index 0000000000..7b5bfbe2ac --- /dev/null +++ b/test/typeparam/absdiffimp.dir/a.go @@ -0,0 +1,75 @@ +// Copyright 2021 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 a + +import ( + "math" +) + +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 +} + +// 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))) +} |