From 58190ccb634ae7931fd6689e1a2c3b5382843ec9 Mon Sep 17 00:00:00 2001 From: angelsl Date: Mon, 3 Oct 2016 23:49:19 +0800 Subject: [PATCH] reference: mention `move` keyword for lambdas --- src/doc/reference.md | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/src/doc/reference.md b/src/doc/reference.md index 20970ab7a3512..b57104fc6f5d9 100644 --- a/src/doc/reference.md +++ b/src/doc/reference.md @@ -3110,10 +3110,12 @@ the lambda expression captures its environment by reference, effectively borrowing pointers to all outer variables mentioned inside the function. Alternately, the compiler may infer that a lambda expression should copy or move values (depending on their type) from the environment into the lambda -expression's captured environment. +expression's captured environment. A lambda can be forced to capture its +environment by moving values by prefixing it with the `move` keyword. In this example, we define a function `ten_times` that takes a higher-order -function argument, and we then call it with a lambda expression as an argument: +function argument, and we then call it with a lambda expression as an argument, +followed by a lambda expression that moves values from its environment. ``` fn ten_times(f: F) where F: Fn(i32) { @@ -3123,6 +3125,9 @@ fn ten_times(f: F) where F: Fn(i32) { } ten_times(|j| println!("hello, {}", j)); + +let word = "konnichiwa".to_owned(); +ten_times(move |j| println!("{}, {}", word, j)); ``` ### Infinite loops