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diff --git a/src/tools/clippy/src/docs/map_identity.txt b/src/tools/clippy/src/docs/map_identity.txt
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+++ b/src/tools/clippy/src/docs/map_identity.txt
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+### What it does
+Checks for instances of `map(f)` where `f` is the identity function.
+
+### Why is this bad?
+It can be written more concisely without the call to `map`.
+
+### Example
+```
+let x = [1, 2, 3];
+let y: Vec<_> = x.iter().map(|x| x).map(|x| 2*x).collect();
+```
+Use instead:
+```
+let x = [1, 2, 3];
+let y: Vec<_> = x.iter().map(|x| 2*x).collect();
+```
+\ No newline at end of file