Creating a struct that contains list types in go

Question

I have created a struct, this struct has contains two list types within it. When I try to instantiate my struct I receive the error

cannot use list.New() (type *list.List) as type list.List in field value

I am using the golang playground

The struct

type myStruct struct {
    name string
    messages list.List
    users list.List
    lastUsed time.Time
}

Instantiating the struct

var myVar = myStruct{"hello", list.New(), list.New(), time.Now()}

Answer 1

list.New() returns a pointer *List , while myStruct announce its fields as List .

func New() *List

messages and users should be *list.List

type myStruct struct {
    name string
    messages *list.List
    users *list.List
    lastUsed time.Time
}

Another approach according to your need, u can just initialize the struct as below:

var myVar = myStruct{"hello", *list.New(), *list.New(), time.Now()}

Answer 2

You are creating wrong struct because go, according to list package New() method returns pointer type of list and you created list in struct without pointer.

func New() *List

So, according to doc you need to created your struct like below:

type myStruct struct {
    name string
    messages *list.List
    users *list.List
    lastUsed time.Time
}

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