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reflect: improve documentation of IsNil
IsNil isn't quite the same as == nil, as this snippet shows: // http://play.golang.org/p/huomslDZgw package main import "fmt" import "reflect" func main() { var i interface{} v := reflect.ValueOf(i) fmt.Println(v.IsValid(), i == nil) fmt.Println(v.IsNil()) } The fact that IsNil panics if you call it with an untyped nil was not apparent. Verbiage added for clarity. LGTM=rsc R=rsc CC=golang-codereviews https://golang.org/cl/65480043
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@ -1091,8 +1091,13 @@ func (v Value) InterfaceData() [2]uintptr {
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return *(*[2]uintptr)(v.ptr)
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}
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// IsNil returns true if v is a nil value.
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// It panics if v's Kind is not Chan, Func, Interface, Map, Ptr, or Slice.
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// IsNil reports whether its argument v is nil. The argument must be
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// a chan, func, interface, map, pointer, or slice value; if it is
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// not, IsNil panics. Note that IsNil is not always equivalent to a
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// regular comparison with nil in Go. For example, if v was created
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// by calling ValueOf with an uninitialized interface variable i,
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// i==nil will be true but v.IsNil will panic as v will be the zero
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// Value.
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func (v Value) IsNil() bool {
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k := v.kind()
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switch k {
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