X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/02337846140cac7ff30e3cc64fd3c9a024bee17c..375923e203d323dadc639434ebc1f29530f4ac2a:/src/part10.rs diff --git a/src/part10.rs b/src/part10.rs index a28b611..39270de 100644 --- a/src/part10.rs +++ b/src/part10.rs @@ -125,10 +125,12 @@ pub fn print_and_count(b: &BigInt) { // then looks for numbers larger than some threshold, and prints them. fn inc_print_threshold(v: &Vec, offset: i32, threshold: i32) { //@ `map` takes a closure that is applied to every element of the iterator. `filter` removes - //@ elements from the iterator that do not pass the test given by the closure. Since all these - //@ closures compile down to the pattern described above, there is actually no heap allocation - //@ going on here. This makes closures very efficient, and it makes optimization fairly - //@ trivial: The resulting code will look like you hand-rolled the loop in C. + //@ elements from the iterator that do not pass the test given by the closure. + //@ + //@ Since all these closures compile down to the pattern described above, there is actually no + //@ heap allocation going on here. This makes closures very efficient, and it makes + //@ optimization fairly trivial: The resulting code will look like you hand-rolled the loop in + //@ C. for i in v.iter().map(|n| *n + offset).filter(|n| *n > threshold) { println!("{}", i); }