return type is not working for a function

[vishcodex]

Bug description

Summary: return statement is not working on a function

Description. While going through the documentation i was testing the functionalities of mojo, when a function with return statement is called in the main function its giving error: cannot implicitly convert 'Int' value to 'None' in return value error. Updating return to print statement is working well.

Environment details: Mac M1
Mojo Compiler Version: mojo 24.4.0
Operating System version: MacOS Sonoma Version 14.5
Hardware Specifications: 32 GB RAM
Severity/frequency: Low

Steps to reproduce

• Include relevant code snippet or link to code that did not work as expected.
• return statement

fn sum_values(*values: Int):
    var sum: Int = 0
    for value in values:
        sum += value
   return sum

fn main() raises:
    var result = sum_values(3,5)

• print statement

fn sum_values(*values: Int):
    var sum: Int = 0
    for value in values:
        sum += value
    print(sum)

fn main() raises:
    var result = sum_values(3,5)

• If applicable, add screenshots to help explain the problem.

with return type :

with print statement:

• If using the Playground, name the pre-existing notebook that failed and the steps that led to failure.
• Include anything else that might help us debug the issue.

System information

- What OS did you do install Mojo on? 
MacOS Sonoma Version 14.5
- Provide version information for Mojo by pasting the output of `mojo -v` 
mojo 24.4.0
- Provide Modular CLI version by pasting the output of `modular -v`
modular 0.8.0

[soraros]

It's not a bug. You have to specify the return type in sum_value:

fn sum_values(*values: Int) -> Int:  # <<<
    var s = 0
    for value in values:
        s += value
   return s

fn main():
    var result = sum_values(3, 5)
    print(result)

print works in the other example because fn f(...): ... is the same as fn f(...) -> None: ....

[vishcodex]

thank you very much!