Rollup merge of #62249 - czipperz:use-mem-take-instead-of-replace-default, r=dtolnay,Centril

Use mem::take instead of mem::replace with default

5 files changed, 6 insertions, 5 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 7353c3ec2e5..8ae96d86657 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -4408,7 +4408,7 @@ pub fn enter_impl_trait<F, R>(cx: &DocContext<'_>, f: F) -> R
 where
     F: FnOnce() -> R,
 {
-    let old_bounds = mem::replace(&mut *cx.impl_trait_bounds.borrow_mut(), Default::default());
+    let old_bounds = mem::take(&mut *cx.impl_trait_bounds.borrow_mut());
     let r = f();
     assert!(cx.impl_trait_bounds.borrow().is_empty());
     *cx.impl_trait_bounds.borrow_mut() = old_bounds;
diff --git a/src/librustdoc/clean/simplify.rs b/src/librustdoc/clean/simplify.rs
index 36e6a6003df..e4fba73b820 100644
--- a/src/librustdoc/clean/simplify.rs
+++ b/src/librustdoc/clean/simplify.rs
@@ -131,7 +131,7 @@ pub fn ty_params(mut params: Vec<clean::GenericParamDef>) -> Vec<clean::GenericP
     for param in &mut params {
         match param.kind {
             clean::GenericParamDefKind::Type { ref mut bounds, .. } => {
-                *bounds = ty_bounds(mem::replace(bounds, Vec::new()));
+                *bounds = ty_bounds(mem::take(bounds));
             }
             _ => panic!("expected only type parameters"),
         }
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 2080637ecb4..2d6503c9445 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -660,7 +660,7 @@ pub fn run(mut krate: clean::Crate,
         deref_trait_did,
         deref_mut_trait_did,
         owned_box_did,
-        masked_crates: mem::replace(&mut krate.masked_crates, Default::default()),
+        masked_crates: mem::take(&mut krate.masked_crates),
         param_names: external_param_names,
         aliases: Default::default(),
     };
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index ba423300e02..342264db43c 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -21,6 +21,7 @@
 #![feature(drain_filter)]
 #![feature(inner_deref)]
 #![feature(never_type)]
+#![feature(mem_take)]
 
 #![recursion_limit="256"]
 
diff --git a/src/librustdoc/passes/collapse_docs.rs b/src/librustdoc/passes/collapse_docs.rs
index 8666ba357b8..144ff226c42 100644
--- a/src/librustdoc/passes/collapse_docs.rs
+++ b/src/librustdoc/passes/collapse_docs.rs
@@ -4,7 +4,7 @@ use crate::fold;
 use crate::fold::{DocFolder};
 use crate::passes::Pass;
 
-use std::mem::replace;
+use std::mem::take;
 
 pub const COLLAPSE_DOCS: Pass = Pass {
     name: "collapse-docs",
@@ -46,7 +46,7 @@ fn collapse(doc_strings: &mut Vec<DocFragment>) {
     let mut docs = vec![];
     let mut last_frag: Option<DocFragment> = None;
 
-    for frag in replace(doc_strings, vec![]) {
+    for frag in take(doc_strings) {
         if let Some(mut curr_frag) = last_frag.take() {
             let curr_kind = curr_frag.kind();
             let new_kind = frag.kind();