goext/langext/maps.go

package langext

func MapKeyArr[T comparable, V any](v map[T]V) []T {
	result := make([]T, 0, len(v))
	for k := range v {
		result = append(result, k)
	}
	return result
}

func ArrToMap[T comparable, V any](a []V, keyfunc func(V) T) map[T]V {
	result := make(map[T]V, len(a))
	for _, v := range a {
		result[keyfunc(v)] = v
	}
	return result
}