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Golang: Using structs as key for Maps
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package main | |
import "fmt" | |
type A struct { | |
a, b int | |
} | |
func MapStructValAsKey(){ | |
// Notice: We are using value of `A`, not `*A` | |
m1 := make(map[A]string) | |
a1 := &A{0, 1} | |
m1[*a1] = "01" | |
a2 := &A{0, 1} | |
// Succeeds because map is hashing with | |
// the `struct` value | |
_, lookSucceed := m1[*a2] | |
fmt.Println(m1, lookSucceed) | |
} | |
func MapStructPointerAsKey(){ | |
// Notice: We are using pointer of `*A`, not `A` | |
m1 := make(map[*A]string) | |
a1 := &A{0, 1} | |
m1[a1] = "01" | |
a2 := &A{0, 1} | |
// Fails because map is hashing with | |
// the `struct` memory address | |
_, lookSucceed := m1[a2] | |
fmt.Println(m1, lookSucceed) | |
} | |
func main() { | |
MapStructValAsKey() | |
MapStructPointerAsKey() | |
} |
yeah.. name of this is misleading
You saved my day .... Thanks.
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You are using a pointer instead of a struct as the key