Thing is, Rust has full support for hygienic macros so operator overloading could've been added as part of that. You'd just have to write, e.g. int_expr![a + b] or whatever, but that would've made the syntax fully extensible.
Macros are easy to spot, the whole point of operator overloading is that it's a trojan horse. It might do simple addition, it might do a heap allocation and talk to a printer.
