Curiosity on the differences from moby/moby#16531 (comment)
$ go test
PASS
ok _/home/vbatts/tmp/string 0.003s
$ go test -run=NONE -bench=. -test.benchmem=true
PASS
BenchmarkString-4 100000 18982 ns/op 0 B/op 0 allocs/op
BenchmarkFmt-4 5000 248974 ns/op 48012 B/op 2000 allocs/op
ok _/home/vbatts/tmp/string 3.369s