Summary

https://doc.rust-lang.org/reference/expressions.html#r-expr.operand-order

GCCRS appears to evaluate child expressions of struct expressions in field definition order, not left to right inside the expression.

Reproducer

#![no_core]

extern "C" {
    fn first_call() -> i32;
    fn second_call() -> i32;
}

pub fn get_0() -> i32 {
    struct S {
        a: i32,
        b: i32
    };

    let x = unsafe {
        S { b: first_call (), a: second_call () }
    };

    x.a
}

Does the code make use of any (1.49) nightly feature ?

• Nightly

Godbolt link

https://godbolt.org/z/9hEoM8YGd

Actual behavior

second_call is called first

Expected behavior

first_call is called first

GCC Version

308bc94