initial commit

sizeofstring/go.mod

@@ -0,0 +1,3 @@
+module git.sunturtle.xyz/zephyr/errors-my-beloved/sizeofstring
+
+go 1.25.0

sizeofstring/step1.go

@@ -0,0 +1,13 @@
+//go:build ignore
+
+// step1.go
+package bocchi
+
+import "unsafe"
+
+type Bocchi struct {
+	x uint32
+	y uint64
+}
+
+var _ [0]struct{} = [unsafe.Sizeof(Bocchi{}) - 0]struct{}{}

sizeofstring/step2.go

@@ -0,0 +1,13 @@
+//go:build ignore
+
+// step2.go
+package bocchi
+
+import "unsafe"
+
+type Bocchi struct {
+	x uint32
+	y uint64
+}
+
+var _ [0]struct{} = [unsafe.Sizeof(Bocchi{}) - 16]struct{}{}

sizeofstring/step3.go

@@ -0,0 +1,18 @@
+package bocchi
+
+import "unsafe"
+
+type Bocchi struct {
+	x uint32
+	y uint64
+}
+
+// step3.go
+var (
+	// assert Bocchi.x doesn't move
+	_ [0]struct{} = [unsafe.Offsetof(Bocchi{}.x) - 0]struct{}{}
+	// assert Bocchi.y comes next after Bocchi.x
+	_ [0]struct{} = [unsafe.Offsetof(Bocchi{}.y) - (unsafe.Alignof(Bocchi{}.y))]struct{}{}
+	// assert y is the last field in Bocchi
+	_ [0]struct{} = [unsafe.Sizeof(Bocchi{}) - (unsafe.Alignof(Bocchi{}.y) + unsafe.Sizeof(Bocchi{}.y))]struct{}{}
+)