- // MIR for `main` before ConstProp + // MIR for `main` after ConstProp fn main() -> () { let mut _0: (); let mut _1: (i32, i32); scope 1 { debug x => _1; let _2: i32; scope 2 { debug y => _2; } } bb0: { StorageLive(_1); _1 = foo() -> bb1; } bb1: { (_1.1: i32) = const 99_i32; (_1.0: i32) = const 42_i32; StorageLive(_2); - _2 = (_1.1: i32); + _2 = const 99_i32; _0 = const (); StorageDead(_2); StorageDead(_1); return; } }