reflect: add CanInt() and friends and uncomments tests that pass

src/reflect/all_test.go

@@ -430,6 +430,8 @@ func TestMapIterSet(t *testing.T) {
 	}
 }
 
+*/
+
 func TestCanIntUintFloatComplex(t *testing.T) {
 	type integer int
 	type uinteger uint
@@ -617,8 +619,6 @@ func TestCanSetField(t *testing.T) {
 	}
 }
 
-*/
-
 var _i = 7
 
 var valueToStringTests = []pair{

src/reflect/value.go

@@ -250,6 +250,16 @@ func (v Value) Bool() bool {
 	}
 }
 
+// CanInt reports whether Uint can be used without panicking.
+func (v Value) CanInt() bool {
+	switch v.Kind() {
+	case Int, Int8, Int16, Int32, Int64:
+		return true
+	default:
+		return false
+	}
+}
+
 func (v Value) Int() int64 {
 	switch v.Kind() {
 	case Int:
@@ -287,6 +297,16 @@ func (v Value) Int() int64 {
 	}
 }
 
+// CanUint reports whether Uint can be used without panicking.
+func (v Value) CanUint() bool {
+	switch v.Kind() {
+	case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr:
+		return true
+	default:
+		return false
+	}
+}
+
 func (v Value) Uint() uint64 {
 	switch v.Kind() {
 	case Uintptr:
@@ -330,6 +350,16 @@ func (v Value) Uint() uint64 {
 	}
 }
 
+// CanFloat reports whether Float can be used without panicking.
+func (v Value) CanFloat() bool {
+	switch v.Kind() {
+	case Float32, Float64:
+		return true
+	default:
+		return false
+	}
+}
+
 func (v Value) Float32() float32 {
 	switch v.Kind() {
 	case Float32:
@@ -377,6 +407,16 @@ func (v Value) Float() float64 {
 	}
 }
 
+// CanComplex reports whether Complex can be used without panicking.
+func (v Value) CanComplex() bool {
+	switch v.Kind() {
+	case Complex64, Complex128:
+		return true
+	default:
+		return false
+	}
+}
+
 func (v Value) Complex() complex128 {
 	switch v.Kind() {
 	case Complex64: