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// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package value
import (
"math"
"reflect"
)
// IsZero reports whether v is the zero value.
// This does not rely on Interface and so can be used on unexported fields.
func IsZero(v reflect.Value) bool {
switch v.Kind() {
case reflect.Bool:
return v.Bool() == false
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return v.Int() == 0
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return v.Uint() == 0
case reflect.Float32, reflect.Float64:
return math.Float64bits(v.Float()) == 0
case reflect.Complex64, reflect.Complex128:
return math.Float64bits(real(v.Complex())) == 0 && math.Float64bits(imag(v.Complex())) == 0
case reflect.String:
return v.String() == ""
case reflect.UnsafePointer:
return v.Pointer() == 0
case reflect.Chan, reflect.Func, reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice:
return v.IsNil()
case reflect.Array:
for i := 0; i < v.Len(); i++ {
if !IsZero(v.Index(i)) {
return false
}
}
return true
case reflect.Struct:
for i := 0; i < v.NumField(); i++ {
if !IsZero(v.Field(i)) {
return false
}
}
return true
}
return false
}
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