constant arrays shouldn't be allowed to be put under mut: struct fields

[zeozeozeo]

V doctor:

V full version: V 0.4.8 5c65e58.df51e84
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: 2024-11-14 18:10:30

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.2024.45-99-gdf51e840
.git/config present: true

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

operable program or batch file.


emcc version: emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.71 (4171ae200b77a6c266b0e1ebb507d61d1ade3501)
thirdparty/tcc status: thirdparty-windows-amd64 b425ac82

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

const arr = [1, 2, 3]

struct Muta {
mut:
	a []int
}

fn main() {
	mut muta := Muta{a: arr}
	muta.a[0] = 52
	println(arr) // [52, 2, 3]
}

What did you expect to see?

compilation error or [1, 2, 3] in stdout

What did you see instead?

[52, 2, 3]

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_{Huly®: V_0.6-21305}

[JalonSolov]

Agreed. It should be copying the const into the field, rather than just pointing to it. The current C code being generated is

VV_LOCAL_SYMBOL void main__main(void) {
        main__Muta muta = ((main__Muta){.a = _const_main__arr,});
        array_set(&muta.a, 0, &(int[]) { 52 });
        println(Array_int_str(_const_main__arr));
}

[Delta456]

The checker needs to raise an error and recommend them to use arr.copy()