fix issue #1607

util/gconv/gconv.go

@@ -279,9 +279,7 @@ func doConvert(in doConvertInput) interface{} {
 
 	default:
 		if in.ReferValue != nil {
-			var (
-				referReflectValue reflect.Value
-			)
+			var referReflectValue reflect.Value
 			if v, ok := in.ReferValue.(reflect.Value); ok {
 				referReflectValue = v
 			} else {

util/gconv/gconv_struct.go

@@ -338,6 +338,12 @@ func bindVarToStructAttr(elem reflect.Value, name string, value interface{}, map
 	if empty.IsNil(value) {
 		structFieldValue.Set(reflect.Zero(structFieldValue.Type()))
 	} else {
+		// Common interface check.
+		var ok bool
+		if err, ok = bindVarToReflectValueWithInterfaceCheck(structFieldValue, value); ok {
+			return err
+		}
+		// Default converting.
 		structFieldValue.Set(reflect.ValueOf(doConvert(
 			doConvertInput{
 				FromValue:  value,
@@ -420,11 +426,6 @@ func bindVarToReflectValue(structFieldValue reflect.Value, value interface{}, ma
 		return nil
 	}
 
-	// Common interface check.
-	if err, ok = bindVarToReflectValueWithInterfaceCheck(structFieldValue, value); ok {
-		return err
-	}
-
 	kind := structFieldValue.Kind()
 	// Converting using interface, for some kinds.
 	switch kind {

util/gconv/gconv_z_unit_scan_test.go

@@ -8,11 +8,13 @@ package gconv_test
 
 import (
 	"fmt"
+	"math/big"
+	"testing"
+
 	"github.com/gogf/gf/v2/container/gvar"
 	"github.com/gogf/gf/v2/frame/g"
 	"github.com/gogf/gf/v2/test/gtest"
 	"github.com/gogf/gf/v2/util/gconv"
-	"testing"
 )
 
 func Test_Scan_StructStructs(t *testing.T) {
@@ -601,3 +603,30 @@ func Test_ScanList_Embedded(t *testing.T) {
 		t.Assert(len(entities[2].UserScores), 0)
 	})
 }
+
+type Float64 float64
+
+func (f *Float64) UnmarshalValue(value interface{}) error {
+	if v, ok := value.(*big.Rat); ok {
+		f64, _ := v.Float64()
+		*f = Float64(f64)
+	}
+	return nil
+}
+
+func Test_Issue1607(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		type Demo struct {
+			B Float64
+		}
+		rat := &big.Rat{}
+		rat.SetFloat64(1.5)
+
+		var demos = make([]Demo, 1)
+		err := gconv.Scan([]map[string]interface{}{
+			{"A": 1, "B": rat},
+		}, &demos)
+		t.AssertNil(err)
+		t.Assert(demos[0].B, 1.5)
+	})
+}