cannot use if-expression on the left side of an indexexpr

[zeozeozeo]

V doctor:

V full version: V 0.4.8 5c65e58.a454f06
OS: windows, Microsoft Windows 10 Pro v19045 64-bit
Processor: 10 cpus, 64bit, little endian, 

getwd: C:\Users\user\Downloads
vexe: C:\Users\user\Desktop\Code\v\v.exe
vexe mtime: 2024-10-25 17:08:19

vroot: OK, value: C:\Users\user\Desktop\Code\v
VMODULES: OK, value: C:\Users\user\.vmodules
VTMP: OK, value: C:\Users\user\AppData\Local\Temp\v_0

Git version: git version 2.42.0.windows.1
Git vroot status: weekly.2024.43-30-ga454f064
.git/config present: true

CC version: Error: 'cc' is not recognized as an internal or external command,

operable program or batch file.


thirdparty/tcc status: thirdparty-windows-amd64 b425ac82

What did you do?
./v -g -o vdbg cmd/v && ./vdbg test.v

fn main() {
    mut array_a := [1, 2, 3]
    mut array_b := [4, 5, 6]
    (if true { array_a } else { array_b })[0] = 999
    println(array_a)
}

What did you expect to see?

[999, 2, 3] printed to stdout or a better error message

What did you see instead?

test.v:4:6: error: unexpected expression `v.ast.IfExpr`
    2 |     mut array_a := [1, 2, 3]
    3 |     mut array_b := [4, 5, 6]
    4 |     (if true { array_a } else { array_b })[0] = 999
      |      ~~
    5 |     println(array_a)
    6 | }

Additional information

The following works, meaning that the result of if true { array_a } else { array_b } can be assigned to:

fn main() {
    mut array_a := [1, 2, 3]
    mut array_b := [4, 5, 6]
    mut arr := if true { array_a } else { array_b }
    arr[0] = 999
    println(array_a)
}

This issue may be related to #22652.

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_{Huly®: V_0.6-21103}