From d90d36dd4c60079c880149d5e0957efed160102d Mon Sep 17 00:00:00 2001
From: Johan Engelen <jbc.engelen@gmail.com>
Date: Tue, 20 Oct 2020 15:09:08 +0200
Subject: [PATCH 1/2] Help compiler deduce `pure` for moveEmplaceImpl

This fixes https://issues.dlang.org/show_bug.cgi?id=21202 .
---
 std/algorithm/mutation.d | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/std/algorithm/mutation.d b/std/algorithm/mutation.d
index 05534221a70..7a8d988d995 100644
--- a/std/algorithm/mutation.d
+++ b/std/algorithm/mutation.d
@@ -1400,7 +1400,7 @@ private T trustedMoveImpl(T)(ref T source) @trusted
     move(x, x);
 }
 
-private void moveEmplaceImpl(T)(ref T source, ref T target)
+private void moveEmplaceImpl(T)(ref T source, ref T target) pure
 {
     import core.stdc.string : memcpy, memset;
     import std.traits : hasAliasing, hasElaborateAssign,
@@ -1517,6 +1517,26 @@ pure nothrow @nogc @system unittest
     f(move(ncarray));
 }
 
+// https://issues.dlang.org/show_bug.cgi?id=21202
+unittest
+{
+    static struct Strukt2
+    {
+        this(int* _block) { }
+    }
+
+    static struct Strukt
+    {
+        int* block;
+        Strukt2 foo() { return Strukt2(null); }
+        alias foo this;
+    }
+
+    Strukt a;
+    Strukt b;
+    moveEmplace(a, b);    
+}
+
 // moveAll
 /**
 Calls `move(a, b)` for each element `a` in `src` and the corresponding

From 1fcbe522e909b9f5b4d752f4046e90aa2b7fc99b Mon Sep 17 00:00:00 2001
From: Johan Engelen <jbc.engelen@gmail.com>
Date: Tue, 20 Oct 2020 15:20:54 +0200
Subject: [PATCH 2/2] whitespace fix

Fixes issue 21202
---
 std/algorithm/mutation.d | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/std/algorithm/mutation.d b/std/algorithm/mutation.d
index 7a8d988d995..10b8ea676a3 100644
--- a/std/algorithm/mutation.d
+++ b/std/algorithm/mutation.d
@@ -1534,7 +1534,7 @@ unittest
 
     Strukt a;
     Strukt b;
-    moveEmplace(a, b);    
+    moveEmplace(a, b);
 }
 
 // moveAll