type switch can modify for loop's variable

[peperronii]

Context

Please provide any relevant information about your setup. This is important in case the issue is not reproducible except for under certain conditions.

Odin:    dev-2024-12-nightly:cf53404
OS:      macOS Ventura 13.6.9 (build 22G830, kernel 22.6.0)
CPU:     Apple M1
RAM:     8192 MiB
Backend: LLVM 18.1.8

Expected Behavior

Type Switch does not modify the variable and the compiler throws an error

Current Behavior

Type switch can modify the variable

Steps to Reproduce

U :: union {
    int,
    bool,
}

ar := [3]U{1, 3, false}

for u in ar {
    switch &v in u {
        case int :
            v = 2  // this should've thrown an error as u should be immutable
            assert(u == 2)
         case bool : 
            v = true // this should too
            assert(u == true)
    }     
}

Failure Logs