Preallocate slices and remove double type assertion

utils/conversions.go

@@ -8,7 +8,7 @@ import (
 
 // MapToStrs takes a map of interfaces and returns a map of strings
 func MapToStrs(aMap map[string]interface{}) map[string]string {
-	results := make(map[string]string)
+	results := make(map[string]string, len(aMap))
 
 	for key, val := range aMap {
 		results[key] = val.(string)
@@ -21,10 +21,10 @@ func MapToStrs(aMap map[string]interface{}) map[string]string {
 
 // ToInts takes a slice of interfaces and returns a slice of ints
 func ToInts(slice []interface{}) []int {
-	results := []int{}
+	results := make([]int, len(slice))
 
-	for _, val := range slice {
+	for i, val := range slice {
-		results = append(results, val.(int))
+		results[i] = val.(int)
 	}
 
 	return results
@@ -32,14 +32,14 @@ func ToInts(slice []interface{}) []int {
 
 // ToStrs takes a slice of interfaces and returns a slice of strings
 func ToStrs(slice []interface{}) []string {
-	results := []string{}
+	results := make([]string, len(slice))
 
-	for _, val := range slice {
+	for i, val := range slice {
-		switch val.(type) {
+		switch t := val.(type) {
 		case int:
-			results = append(results, strconv.Itoa(val.(int)))
+			results[i] = strconv.Itoa(t)
 		case string:
-			results = append(results, val.(string))
+			results[i] = t
 		}
 	}