add unsafeext package

go.mod

@@ -1,8 +1,9 @@
 module github.com/go-playground/pkg/v4
 
 require (
+	github.com/go-playground/assert v1.2.1 // indirect
 	github.com/go-playground/assert/v2 v2.0.1
-	github.com/go-playground/form/v4 v4.0.0
+	github.com/go-playground/form/v4 v4.1.1
 )
 
-go 1.13
+go 1.14

go.sum

@@ -4,3 +4,5 @@ github.com/go-playground/assert/v2 v2.0.1 h1:MsBgLAaY856+nPRTKrp3/OZK38U/wa0CcBY
 github.com/go-playground/assert/v2 v2.0.1/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
 github.com/go-playground/form/v4 v4.0.0 h1:vUKi2K1Hqlc4rpBc0tCclgs9zSfbY5yMKsL106db/eY=
 github.com/go-playground/form/v4 v4.0.0/go.mod h1:bodWfd97U9PVMZFcDsbVzSbQQTtaWrebnTwQtWjSW1M=
+github.com/go-playground/form/v4 v4.1.1 h1:1T9lGt3WRHuDwT5uwx7RYQZfxVwWZhF0DC1ovKyNnWY=
+github.com/go-playground/form/v4 v4.1.1/go.mod h1:q1a2BY+AQUUzhl6xA/6hBetay6dEIhMHjgvJiGo6K7U=

unsafe/conversions.go

@@ -0,0 +1,23 @@
+package unsafeext
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// BytesToString converts an array of bytes into a string without allocating.
+// The byte slice passed to this function is not to be used after this call as it's unsafe; you have been warned.
+func BytesToString(b []byte) string {
+	return *(*string)(unsafe.Pointer(&b))
+}
+
+// StringToBytes converts an existing string into an []byte without allocating.
+// The string passed to this functions is not to be used again after this call as it's unsafe; you have been warned.
+func StringToBytes(s string) (b []byte) {
+	strHdr := (*reflect.StringHeader)(unsafe.Pointer(&s))
+	sliceHdr := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+	sliceHdr.Data = strHdr.Data
+	sliceHdr.Cap = strHdr.Len
+	sliceHdr.Len = strHdr.Len
+	return
+}

unsafe/conversions_test.go

@@ -0,0 +1,21 @@
+package unsafeext
+
+import "testing"
+
+func TestBytesToString(t *testing.T) {
+	b := []byte{'g', 'o', '-', 'p', 'l', 'a', 'y', 'g', 'r', 'o', 'u', 'n', 'd'}
+	s := BytesToString(b)
+	expected := string(b)
+	if s != expected {
+		t.Fatalf("expected '%s' got '%s'", expected, s)
+	}
+}
+
+func TestStringToBytes(t *testing.T) {
+	s := "go-playground"
+	b := StringToBytes(s)
+
+	if string(b) != s {
+		t.Fatalf("expected '%s' got '%s'", s, string(b))
+	}
+}