Add support for conversion between numeric types

config.go

@@ -150,19 +150,19 @@ func setDstElem(dst interface{}, field *structs.Field, fVal string) error {
 		} else {
 			dstElem.SetBool(p)
 		}
-	case "int":
+	case "int", "int8", "int16", "int32", "int64":
 		if p, err := strconv.ParseInt(fVal, 10, 0); err != nil {
 			return err
 		} else {
 			dstElem.SetInt(p)
 		}
-	case "uint":
+	case "uint", "uint8", "uint16", "uint32", "uint64", "uintptr":
 		if p, err := strconv.ParseUint(fVal, 10, 0); err != nil {
 			return err
 		} else {
 			dstElem.SetUint(p)
 		}
-	case "float64":
+	case "float64", "float32":
 		if p, err := strconv.ParseFloat(fVal, 64); err != nil {
 			return err
 		} else {

config_test.go

@@ -470,6 +470,7 @@ func TestLoad_ErrorIfFlagTypeMismatch(t *testing.T) {
 	}
 
 	tmp, _ := ioutil.TempFile("", "")
+	defer os.Remove(tmp.Name())
 
 	// flag
 	fs := flag.NewFlagSet("tmp", flag.ExitOnError)
@@ -489,6 +490,7 @@ func TestLoad_ErrorIfEnvTypeMismatch(t *testing.T) {
 	}
 
 	tmp, _ := ioutil.TempFile("", "")
+	defer os.Remove(tmp.Name())
 
 	// env
 	os.Setenv("key_float", "key_float_env")
@@ -497,3 +499,72 @@ func TestLoad_ErrorIfEnvTypeMismatch(t *testing.T) {
 		t.Fatalf("expected error, got nil")
 	}
 }
+
+func TestLoad_CheckNumericTypes(t *testing.T) {
+	var cfg struct {
+		Float32 float32 `flag:"float32"`
+		Int8    int8    `toml:"int8"`
+		Int16   int16   `env:"int16"`
+		Uint32  uint32  `toml:"uint32"`
+		Uint64  uint64  `env:"uint64"`
+		UintPtr uintptr `env:"uintptr"`
+		Bool    bool    `flag:"bool"`
+	}
+
+	tmp, _ := ioutil.TempFile("", "")
+	defer os.Remove(tmp.Name())
+
+	_, err := tmp.WriteString(`
+int8 = -2
+uint32 = 1
+`)
+	if err != nil {
+		t.Fatalf("write config file failed: %v", err)
+	}
+
+	// flag
+	fs := flag.NewFlagSet("tmp", flag.ExitOnError)
+	_ = fs.Bool("bool", false, "")
+	_ = fs.Float64("float32", 0.0, "")
+
+	flag.CommandLine = fs
+	flag.CommandLine.Parse([]string{"-bool", "true"})   // flag given
+	flag.CommandLine.Parse([]string{"-float32", "1.3"}) // flag given
+
+	// env
+	os.Setenv("uint64", "100000000000")
+	os.Setenv("uintptr", "20")
+	os.Setenv("int16", "3")
+
+	if err := Load(tmp.Name(), &cfg); err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+
+	if cfg.Float32 != 1.3 {
+		t.Errorf("got: %v, expected: %v", cfg.Float32, 1.3)
+	}
+
+	if cfg.Int8 != -2 {
+		t.Errorf("got: %v, expected: %v", cfg.Int8, -2)
+	}
+
+	if cfg.Int16 != 3 {
+		t.Errorf("got: %v, expected: %v", cfg.Int16, 3)
+	}
+
+	if cfg.Uint32 != 1 {
+		t.Errorf("got: %v, expected: %v", cfg.Uint32, 1)
+	}
+
+	if cfg.Uint64 != 100000000000 {
+		t.Errorf("got: %v, expected: %v", cfg.Uint64, 100000000000)
+	}
+
+	if cfg.UintPtr != 20 {
+		t.Errorf("got: %v, expected: %v", cfg.UintPtr, 20)
+	}
+
+	if cfg.Bool != true {
+		t.Errorf("got: %v, expected: %v", cfg.Bool, true)
+	}
+}