Underscore variables

[mcfilib]

When I set up my mock but I only use an underscore as the variable (see example below), the mock doesn't get created. Why does this happen when I use let _ but not let _m? Is the call being optimised away by the compiler? Is it worth adding a note in the documentation?

  let _ = mock("GET", "/recordings?device_id=0000")
    .with_status(201)
    .with_header("content-type", "text/plain")
    .with_body(json_body) // some json string
    .create();

Versions

rustc 1.22.0-nightly (d7e73e4b1 2017-10-04)
mockito-0.9.0

[lipanski]

good point. I've clarified this in 1205b59

I'm actually not sure why Rust treats the _ this way, but it's definitly a consistent behaviour. I've found this RFC but I'm still not exactly sure what the story behind this is.

[ozkriff]

I'm actually not sure why Rust treats the _ this way

Saying "variable named _" is incorrect, as _ isn't a variable (binding), it's just a part of a pattern matching syntax, like mut, ref, | etc.

[lipanski]

@ozkriff good point. I tried to be more correct in 55d36f3