Исходники и презентации

lessons/structs/union_1/main.go

@@ -0,0 +1,22 @@
+package main
+
+import "unsafe"
+
+// SBO (Small Buffer Optimization)
+type SBO struct {
+	size  int64
+	union [16]byte // 8B[pointer]8B[capacity]
+}
+
+func main() {
+	var small SBO
+	small.size = 10
+	small.union = [16]byte{}
+
+	var big SBO
+	big.size = 1024
+	pointer := (*[2048]byte)(unsafe.Pointer(&big.union))
+	*pointer = [2048]byte{}
+	capacity := (*int64)(unsafe.Add(unsafe.Pointer(&big.union), 8))
+	*capacity = 2048
+}