Re: How to fake a const method ?

[Basile B. via Digitalmars-d-learn]

On Friday, 9 March 2018 at 13:47:34 UTC, Basile B. wrote:
I would need this to work:
```
struct Foo
{
    TypeInfo typeCache;

    TypeInfo getTypeCache()
    {
        alias NotThePoint = ubyte;
        if (typeCache is null)
            typeCache = typeid(NotThePoint);
        return typeCache;
    }

    TypeInfo type() const
    {
        alias NothrowType = TypeInfo delegate() const;
        return (cast(NothrowType) &getTypeCache)();
    }
}

void main(){}
```

But get:

Error: mutable method `Foo.getTypeCache` is not callable using 
a `const` `this`


- `type()` really has to be const because it's used in an 
opEquals that's used by an AA (key is const so opEquals has to 
as well)
- `typeCache` is not used to compare 2 Foos so it really 
doesn't matter if it get assigned.

Solved...The error message helped much actually... problem is 
`this` is `const`

https://run.dlang.io/is/UOR2i2