在 struct panics 的字段上調(diào)用 atomic.AddInt64 invalid memory address or nil pointer dereference，但在我們重新排列字段順序時(shí)不會(huì)；為什么？使用這種類型：type CountHandler struct {    c     *RequestContext    count int64}并且調(diào)用atomic.AddInt64(&countHandler.count, 1)（此時(shí)字段c為零）恐慌。但當(dāng)我們將其重寫(xiě)為：type CountHandler struct {    count int64    c     *RequestContext}錯(cuò)誤消失。我想應(yīng)該是這樣，因?yàn)?Go 以順序方式將數(shù)據(jù)保存在內(nèi)存中，并且達(dá)到一個(gè)nil值會(huì)破壞這個(gè)（字節(jié)）序列；但我想知道為什么又是這樣，因?yàn)橹羔槕?yīng)該具有固定大小nil或其他值。這是 Windows 上的 Go x86 1.4.2，完整的錯(cuò)誤消息是：2015/02/23 12:56:44 http: panic serving [::1]:51886: runtime error: invalid memory address or nil pointer dereferencegoroutine 5 [running]:net/http.func·011()        c:/go/src/net/http/server.go:1130 +0xa8sync/atomic.AddUint64(0x731144, 0x1, 0x0, 0x0, 0x263168)        c:/go/src/sync/atomic/asm_386.s:118 +0xcmain.(*CountHandler).ServeHTTP(0x731140, 0x263180, 0x122f6380, 0x122f62a0)        C:/Workshop/Devox/Workshop-Go/src/geoho/web/app/app.go:62 +0x42github.com/julienschmidt/httprouter.func·001(0x263180, 0x122f6380, 0x122f62a0, 0x0, 0x0, 0x0)        C:/Workshop/Devox/Workshop-Go/src/github.com/julienschmidt/httprouter/router.go:232 +0x4cgithub.com/julienschmidt/httprouter.(*Router).ServeHTTP(0x122d5d20, 0x263180, 0x122f6380, 0x122f62a0)        C:/Workshop/Devox/Workshop-Go/src/github.com/julienschmidt/httprouter/router.go:298 +0x141net/http.serverHandler.ServeHTTP(0x122d2280, 0x263180, 0x122f6380, 0x122f62a0)        c:/go/src/net/http/server.go:1703 +0x145net/http.(*conn).serve(0x122e01e0)        c:/go/src/net/http/server.go:1204 +0x9d8created by net/http.(*Server).Serve        c:/go/src/net/http/server.go:1751 +0x2ce