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EddTests

•Created by EddTests on 9/8/2023 in #questions

error: expression must be mutable in assignment

I'm trying to create a fibonacci struct:

struct Fib:
    var a: Int
    var b: Int

    fn __init__(inout self):
        self.a = 0
        self.b = 1

    fn generate(self) -> Int:
        var new_value = self.a + self.b
        if self.a > self.b:
            self.b = new_value
        else:
            self.a = new_value

        return new_value

struct Fib:
    var a: Int
    var b: Int

    fn __init__(inout self):
        self.a = 0
        self.b = 1

    fn generate(self) -> Int:
        var new_value = self.a + self.b
        if self.a > self.b:
            self.b = new_value
        else:
            self.a = new_value

        return new_value

However it's failing with this error:

@eddtests ➜ /workspaces/mojo-etudes (main) $ mojo ./project-euler/0002.🔥 
./project-euler/0002.🔥:14:17: error: expression must be mutable in assignment
            self.b = new_value
            ~~~~^~
./project-euler/0002.🔥:16:17: error: expression must be mutable in assignment
            self.a = new_value
            ~~~~^~
mojo: error: failed to parse the provided Mojo

@eddtests ➜ /workspaces/mojo-etudes (main) $ mojo ./project-euler/0002.🔥 
./project-euler/0002.🔥:14:17: error: expression must be mutable in assignment
            self.b = new_value
            ~~~~^~
./project-euler/0002.🔥:16:17: error: expression must be mutable in assignment
            self.a = new_value
            ~~~~^~
mojo: error: failed to parse the provided Mojo

Any hints on what I need to do to be able to update the values in the struct? I thought inout self was enough

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