TypeTooLarge occurs if unsafe.Sizeof or unsafe.Offsetof is called with an expression whose type is too large. Example: import "unsafe" type E [1 {{raw "<"}}{{raw "<"}} 31 - 1]int var a [1 {{raw "<"}}{{raw "<"}} 31]E var _ = unsafe.Sizeof(a) Example: import "unsafe" type E [1 {{raw "<"}}{{raw "<"}} 31 - 1]int var s struct { _ [1 {{raw "<"}}{{raw "<"}} 31]E x int } var _ = unsafe.Offsetof(s.x)