From ccd992355df7192993c666236047820244914598 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:19:13 +0200 Subject: Adding upstream version 1.21.8. Signed-off-by: Daniel Baumann --- src/cmp/cmp.go | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 src/cmp/cmp.go (limited to 'src/cmp/cmp.go') diff --git a/src/cmp/cmp.go b/src/cmp/cmp.go new file mode 100644 index 0000000..0fba5c1 --- /dev/null +++ b/src/cmp/cmp.go @@ -0,0 +1,59 @@ +// Copyright 2023 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 cmp provides types and functions related to comparing +// ordered values. +package cmp + +// Ordered is a constraint that permits any ordered type: any type +// that supports the operators < <= >= >. +// If future releases of Go add new ordered types, +// this constraint will be modified to include them. +// +// Note that floating-point types may contain NaN ("not-a-number") values. +// An operator such as == or < will always report false when +// comparing a NaN value with any other value, NaN or not. +// See the [Compare] function for a consistent way to compare NaN values. +type Ordered interface { + ~int | ~int8 | ~int16 | ~int32 | ~int64 | + ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr | + ~float32 | ~float64 | + ~string +} + +// Less reports whether x is less than y. +// For floating-point types, a NaN is considered less than any non-NaN, +// and -0.0 is not less than (is equal to) 0.0. +func Less[T Ordered](x, y T) bool { + return (isNaN(x) && !isNaN(y)) || x < y +} + +// Compare returns +// +// -1 if x is less than y, +// 0 if x equals y, +// +1 if x is greater than y. +// +// For floating-point types, a NaN is considered less than any non-NaN, +// a NaN is considered equal to a NaN, and -0.0 is equal to 0.0. +func Compare[T Ordered](x, y T) int { + xNaN := isNaN(x) + yNaN := isNaN(y) + if xNaN && yNaN { + return 0 + } + if xNaN || x < y { + return -1 + } + if yNaN || x > y { + return +1 + } + return 0 +} + +// isNaN reports whether x is a NaN without requiring the math package. +// This will always return false if T is not floating-point. +func isNaN[T Ordered](x T) bool { + return x != x +} -- cgit v1.2.3