如何在函数中将字符串值转换为自定义类型

Question

我编写了一个用于角色检查的函数：...role = "roles/cloudkms.publicKeyViewer"func checkRole(key, serviceAccount, role string) bool {...return policy.HasRole(serviceAccount, role)}然后我收到错误“不能在 policy.HasRole 的参数中使用角色（类型字符串）作为类型“cloud.google.com/go/iam”.RoleName。将角色值转换为自定义类型的正确方法是什么？图书馆：// A RoleName is a name representing a collection of permissions.type RoleName string// Common role names.const (    Owner  RoleName = "roles/owner"    Editor RoleName = "roles/editor"    Viewer RoleName = "roles/viewer")const (    // AllUsers is a special member that denotes all users, even unauthenticated ones.    AllUsers = "allUsers"    // AllAuthenticatedUsers is a special member that denotes all authenticated users.    AllAuthenticatedUsers = "allAuthenticatedUsers")// HasRole reports whether member has role r.func (p *Policy) HasRole(member string, r RoleName) bool {    return memberIndex(member, p.binding(r)) >= 0}

Answer 1

您可以使用类型转换，如下所示：

return policy.HasRole(serviceAccount, iam.RoleName(role))

或者通过将角色声明为更简单iam.RoleName

func checkRole(key, serviceAccount, role iam.RoleName) bool {

...

   return policy.HasRole(serviceAccount, role)

}