diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs
index 7dcb03b4c78..6fed0b660e8 100644
--- a/compiler/rustc_ast/src/mut_visit.rs
+++ b/compiler/rustc_ast/src/mut_visit.rs
@@ -12,7 +12,7 @@ use crate::ptr::P;
 use crate::token::{self, Token};
 use crate::tokenstream::*;
 
-use rustc_data_structures::map_in_place::MapInPlace;
+use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
 use rustc_data_structures::sync::Lrc;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::Ident;
diff --git a/compiler/rustc_data_structures/src/map_in_place.rs b/compiler/rustc_data_structures/src/flat_map_in_place.rs
similarity index 87%
rename from compiler/rustc_data_structures/src/map_in_place.rs
rename to compiler/rustc_data_structures/src/flat_map_in_place.rs
index a0d4b7ade1f..f58844f2817 100644
--- a/compiler/rustc_data_structures/src/map_in_place.rs
+++ b/compiler/rustc_data_structures/src/flat_map_in_place.rs
@@ -2,14 +2,7 @@ use smallvec::{Array, SmallVec};
 use std::ptr;
 use thin_vec::ThinVec;
 
-pub trait MapInPlace<T>: Sized {
-    fn map_in_place<F>(&mut self, mut f: F)
-    where
-        F: FnMut(T) -> T,
-    {
-        self.flat_map_in_place(|e| Some(f(e)))
-    }
-
+pub trait FlatMapInPlace<T>: Sized {
     fn flat_map_in_place<F, I>(&mut self, f: F)
     where
         F: FnMut(T) -> I,
@@ -66,14 +59,14 @@ macro_rules! flat_map_in_place {
     };
 }
 
-impl<T> MapInPlace<T> for Vec<T> {
+impl<T> FlatMapInPlace<T> for Vec<T> {
     flat_map_in_place!();
 }
 
-impl<T, A: Array<Item = T>> MapInPlace<T> for SmallVec<A> {
+impl<T, A: Array<Item = T>> FlatMapInPlace<T> for SmallVec<A> {
     flat_map_in_place!();
 }
 
-impl<T> MapInPlace<T> for ThinVec<T> {
+impl<T> FlatMapInPlace<T> for ThinVec<T> {
     flat_map_in_place!();
 }
diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
index a94e52fdfe6..c595bf830a3 100644
--- a/compiler/rustc_data_structures/src/lib.rs
+++ b/compiler/rustc_data_structures/src/lib.rs
@@ -50,6 +50,7 @@ pub fn cold_path<F: FnOnce() -> R, R>(f: F) -> R {
 pub mod base_n;
 pub mod binary_search_util;
 pub mod captures;
+pub mod flat_map_in_place;
 pub mod flock;
 pub mod functor;
 pub mod fx;
@@ -57,7 +58,6 @@ pub mod graph;
 pub mod intern;
 pub mod jobserver;
 pub mod macros;
-pub mod map_in_place;
 pub mod obligation_forest;
 pub mod owning_ref;
 pub mod sip128;
diff --git a/compiler/rustc_expand/src/config.rs b/compiler/rustc_expand/src/config.rs
index 01500c2c77c..d6cb173ba9b 100644
--- a/compiler/rustc_expand/src/config.rs
+++ b/compiler/rustc_expand/src/config.rs
@@ -12,8 +12,8 @@ use rustc_ast::tokenstream::{LazyAttrTokenStream, TokenTree};
 use rustc_ast::NodeId;
 use rustc_ast::{self as ast, AttrStyle, Attribute, HasAttrs, HasTokens, MetaItem};
 use rustc_attr as attr;
+use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
 use rustc_data_structures::fx::FxHashMap;
-use rustc_data_structures::map_in_place::MapInPlace;
 use rustc_feature::{Feature, Features, State as FeatureState};
 use rustc_feature::{
     ACCEPTED_FEATURES, ACTIVE_FEATURES, REMOVED_FEATURES, STABLE_REMOVED_FEATURES,
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index 79d058d9c97..4092a192e0c 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -20,7 +20,7 @@ use rustc_ast::{ForeignItemKind, HasAttrs, HasNodeId};
 use rustc_ast::{Inline, ItemKind, MacStmtStyle, MetaItemKind, ModKind};
 use rustc_ast::{NestedMetaItem, NodeId, PatKind, StmtKind, TyKind};
 use rustc_ast_pretty::pprust;
-use rustc_data_structures::map_in_place::MapInPlace;
+use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::PResult;
 use rustc_feature::Features;