Add AppendInt function with positive/negative number convertion to st…

…ring

Benchmark_ItoA/fiber             (pos_num)-12  190428255        6.13 ns/op       0 B/op       0 allocs/op
Benchmark_ItoA/fiber             (pos_num)-12  196626811        6.08 ns/op       0 B/op       0 allocs/op
Benchmark_ItoA/strconv.Itoa      (pos_num)-12   80716807       14.33 ns/op       4 B/op       1 allocs/op
Benchmark_ItoA/strconv.Itoa      (pos_num)-12   80445802       14.30 ns/op       4 B/op       1 allocs/op
Benchmark_ItoA/strconv.FormatInt_(pos_num)-12   81137728       14.30 ns/op       4 B/op       1 allocs/op
Benchmark_ItoA/strconv.FormatInt_(pos_num)-12   81345360       14.49 ns/op       4 B/op       1 allocs/op
Benchmark_ItoA/fiber             (neg_num)-12  151121002        7.81 ns/op       0 B/op       0 allocs/op
Benchmark_ItoA/fiber             (neg_num)-12  153566410        7.70 ns/op       0 B/op       0 allocs/op
Benchmark_ItoA/strconv.Itoa      (neg_num)-12   84505304       13.75 ns/op       5 B/op       1 allocs/op
Benchmark_ItoA/strconv.Itoa      (neg_num)-12   82524801       13.76 ns/op       5 B/op       1 allocs/op
Benchmark_ItoA/strconv.FormatInt (neg_num)-12   84884136       13.88 ns/op       5 B/op       1 allocs/op
Benchmark_ItoA/strconv.FormatInt (neg_num)-12   85829492       13.76 ns/op       5 B/op       1 allocs/op

convert_test.go

@@ -259,19 +259,6 @@ func Benchmark_ToString(b *testing.B) {
 	}
 }
 
-func Benchmark_ToString_string(b *testing.B) {
-	res := ""
-	expectedRes := "4242"
-	b.ReportAllocs()
-	b.ResetTimer()
-
-	for i := 0; i < b.N; i++ {
-		res = ToString(4242)
-	}
-
-	require.Equal(b, expectedRes, res)
-}
-
 // go test -v -run=^$ -bench=ToString_concurrency -benchmem -count=4
 func Benchmark_ToString_concurrency(b *testing.B) {
 	for _, value := range dataTypeExamples {