output.md

$ for i in seq 1 3; do go test -bench=. -benchtime=5s; echo; done
goos: linux
goarch: amd64
pkg: github.com/Scout24/go-observability/.local
BenchmarkCallWithoutSlice-4    	100000000	        76.8 ns/op
BenchmarkCallWithSlice-4       	100000000	        77.1 ns/op
BenchmarkCallWithSliceCopy-4   	100000000	        76.4 ns/op
PASS
ok  	github.com/Scout24/go-observability/.local	23.277s

goos: linux
goarch: amd64
pkg: github.com/Scout24/go-observability/.local
BenchmarkCallWithoutSlice-4    	100000000	        77.0 ns/op
BenchmarkCallWithSlice-4       	100000000	        77.6 ns/op
BenchmarkCallWithSliceCopy-4   	100000000	        76.8 ns/op
PASS
ok  	github.com/Scout24/go-observability/.local	23.406s

goos: linux
goarch: amd64
pkg: github.com/Scout24/go-observability/.local
BenchmarkCallWithoutSlice-4    	100000000	        78.3 ns/op
BenchmarkCallWithSlice-4       	100000000	        80.6 ns/op
BenchmarkCallWithSliceCopy-4   	100000000	        83.3 ns/op
PASS
ok  	github.com/Scout24/go-observability/.local	24.502s

slice_test.go

package _local

import (
	"strings"
	"testing"
)

var globalSlice = []string{"a", "b", "c"}

func callWithoutSlice(a string) string {
	return a + ":" + strings.Join(globalSlice, ":")
}

func callWithSlice(a string, in []string) string {
	return a + ":" + strings.Join(in, ":")
}

func BenchmarkCallWithoutSlice(b *testing.B) {
	for i := 0; i < b.N; i++ {
		callWithoutSlice("X")
	}
}

func BenchmarkCallWithSlice(b *testing.B) {
	for i := 0; i < b.N; i++ {
		callWithSlice("X", []string{"a", "b", "c"})
	}
}

func BenchmarkCallWithSliceCopy(b *testing.B) {
	from := []string{"a", "b", "c"}
	for i := 0; i < b.N; i++ {
		callWithSlice("X", from[:])
	}
}