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| author | Jonathan Strong <jstrong@legis.io> | 2017-12-06 20:30:57 -0500 |
|---|---|---|
| committer | Jonathan Strong <jstrong@legis.io> | 2017-12-06 20:30:57 -0500 |
| commit | 9307917d6abc115faf7d2cb625c550cb509b5c4d (patch) | |
| tree | 6ef393abc08b8eb501e71114ac41871f5c8a2732 | |
| parent | 9f3b09116b742b2606dc5f36f9145e0c89e4010b (diff) | |
| download | rust-9307917d6abc115faf7d2cb625c550cb509b5c4d.tar.gz rust-9307917d6abc115faf7d2cb625c550cb509b5c4d.zip | |
Adds language to the documentation for `Option` and `Result` suggesting
the use of lazily evaluated alternatives when appropriate. These comments are intended to echo a clippy lint on the same topic (see https://rust-lang-nursery.github.io/rust-clippy/master/index.html#or_fun_call)
| -rw-r--r-- | src/libcore/option.rs | 12 | ||||
| -rw-r--r-- | src/libcore/result.rs | 8 |
2 files changed, 20 insertions, 0 deletions
diff --git a/src/libcore/option.rs b/src/libcore/option.rs index 980ea551f08..e354c7e16a1 100644 --- a/src/libcore/option.rs +++ b/src/libcore/option.rs @@ -338,6 +338,10 @@ impl<T> Option<T> { /// Returns the contained value or a default. /// + /// Arguments passed to `unwrap_or` are eagerly evaluated; if you are passing + /// the result of a function call, it is recommended to use `unwrap_or_else`, + /// which is lazily evaluated. + /// /// # Examples /// /// ``` @@ -451,6 +455,10 @@ impl<T> Option<T> { /// Transforms the `Option<T>` into a [`Result<T, E>`], mapping [`Some(v)`] to /// [`Ok(v)`] and [`None`] to [`Err(err)`]. /// + /// Arguments passed to `ok_or` are eagerly evaluated; if you are passing the + /// result of a function call, it is recommended to use `ok_or_else`, which is + /// lazily evaluated. + /// /// [`Result<T, E>`]: ../../std/result/enum.Result.html /// [`Ok(v)`]: ../../std/result/enum.Result.html#variant.Ok /// [`Err(err)`]: ../../std/result/enum.Result.html#variant.Err @@ -609,6 +617,10 @@ impl<T> Option<T> { /// Returns the option if it contains a value, otherwise returns `optb`. /// + /// Arguments passed to `or` are eagerly evaluated; if you are passing the + /// result of a function call, it is recommended to use `or_else`, which is + /// lazily evaluated. + /// /// # Examples /// /// ``` diff --git a/src/libcore/result.rs b/src/libcore/result.rs index db5bffced10..438b3ed46a1 100644 --- a/src/libcore/result.rs +++ b/src/libcore/result.rs @@ -625,6 +625,10 @@ impl<T, E> Result<T, E> { /// Returns `res` if the result is [`Err`], otherwise returns the [`Ok`] value of `self`. /// + /// Arguments passed to `or` are eagerly evaluated; if you are passing the + /// result of a function call, it is recommended to use `or_else`, which is + /// lazily evaluated. + /// /// [`Ok`]: enum.Result.html#variant.Ok /// [`Err`]: enum.Result.html#variant.Err /// @@ -690,6 +694,10 @@ impl<T, E> Result<T, E> { /// Unwraps a result, yielding the content of an [`Ok`]. /// Else, it returns `optb`. /// + /// Arguments passed to `unwrap_or` are eagerly evaluated; if you are passing + /// the result of a function call, it is recommended to use `unwrap_or_else`, + /// which is lazily evaluated. + /// /// [`Ok`]: enum.Result.html#variant.Ok /// [`Err`]: enum.Result.html#variant.Err /// |