From 0b322656db5f4d5b505fa7841a206b43d1b85414 Mon Sep 17 00:00:00 2001
From: Leandro Lucarella <llucax@gmail.com>
Date: Sun, 6 Sep 2009 17:26:03 -0300
Subject: [PATCH] Compare pointers explicitly against null using is and !is

---
 gc/cell.d     |  2 +-
 gc/dynarray.d | 12 ++++++------
 gc/gc.d       | 22 +++++++++++-----------
 gc/list.d     | 14 +++++++-------
 4 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/gc/cell.d b/gc/cell.d
index b8261de..cd8fae1 100644
--- a/gc/cell.d
+++ b/gc/cell.d
@@ -182,7 +182,7 @@ private:
         auto N = 10;
         auto size = N * size_t.sizeof;
         auto cell = Cell.alloc(size, BlkAttr.FINALIZE | BlkAttr.NO_SCAN);
-        assert (cell);
+        assert (cell !is null);
         assert (cell.ptr is cell + 1);
         for (int i = 0; i < N; ++i) {
             auto ptr = cast(size_t*) cell.ptr + i;
diff --git a/gc/dynarray.d b/gc/dynarray.d
index 9836258..bd387cf 100644
--- a/gc/dynarray.d
+++ b/gc/dynarray.d
@@ -153,19 +153,19 @@ private:
         DynArray!(int) array;
         assert (array.size == 0);
         assert (array.capacity == 0);
-        assert (array.data == null);
+        assert (array.data is null);
         foreach (x; array)
             assert (false, "there should be no elements in the array");
         array.append(5);
         assert (array.size == 1);
         assert (array.capacity >= 1);
-        assert (array.data);
+        assert (array.data !is null);
         foreach (x; array)
             assert (x == 5);
         array.append(6);
         assert (array.size == 2);
         assert (array.capacity >= 2);
-        assert (array.data);
+        assert (array.data !is null);
         int i = 0;
         foreach (x; array)
             assert (x == 5 + i++);
@@ -173,19 +173,19 @@ private:
         array.remove(5);
         assert (array.size == 1);
         assert (array.capacity >= 1);
-        assert (array.data);
+        assert (array.data !is null);
         foreach (x; array)
             assert (x == 6);
         array.expand(100);
         assert (array.size == 1);
         assert (array.capacity >= 100);
-        assert (array.data);
+        assert (array.data !is null);
         foreach (x; array)
             assert (x == 6);
         array.clear();
         assert (array.size == 0);
         assert (array.capacity == 0);
-        assert (array.data == null);
+        assert (array.data is null);
         foreach (x; array)
             assert (false, "there should be no elements in the array");
     }
diff --git a/gc/gc.d b/gc/gc.d
index dfe084b..a10143a 100644
--- a/gc/gc.d
+++ b/gc/gc.d
@@ -455,7 +455,7 @@ public:
     uint getAttr(void* ptr)
     {
         auto cell = this.live_list.find(ptr);
-        if (cell)
+        if (cell !is null)
             return cell.attr;
         return 0;
     }
@@ -471,7 +471,7 @@ public:
     uint setAttr(void* ptr, uint attr)
     {
         auto cell = this.live_list.find(ptr);
-        if (cell) {
+        if (cell !is null) {
             auto old = cell.attr;
             cell.attr |= attr;
             return cell.attr;
@@ -490,7 +490,7 @@ public:
     uint clrAttr(void* ptr, uint attr)
     {
         auto cell = this.live_list.find(ptr);
-        if (cell) {
+        if (cell !is null) {
             auto old = cell.attr;
             cell.attr &= ~attr;
             return cell.attr;
@@ -518,7 +518,7 @@ public:
 
         // Find a free cell in the free list with enough space
         auto cell = this.free_list.pop(size);
-        if (cell)
+        if (cell !is null)
             goto reuse;
 
         // No room in the free list found, if the GC is enabled, trigger
@@ -526,13 +526,13 @@ public:
         if (!this.disabled) {
             this.collect();
             cell = this.free_list.pop(size);
-            if (cell)
+            if (cell !is null)
                 goto reuse;
         }
 
         // No luck still, allocate a new cell
         cell = Cell.alloc(size, attr);
-        if (cell)
+        if (cell !is null)
             goto link;
 
         // No memory
@@ -592,7 +592,7 @@ public:
         }
 
         auto cell = this.live_list.find(ptr);
-        assert (cell);
+        assert (cell !is null);
 
         // We have enough capacity already, just change the size
         if (cell.capacity >= size) {
@@ -675,7 +675,7 @@ public:
             return;
 
         auto cell = this.live_list.pop(ptr);
-        assert (cell);
+        assert (cell !is null);
 
         this.free_list.link(cell);
     }
@@ -696,7 +696,7 @@ public:
         }
 
         auto cell = this.live_list.find(&in_range);
-        if (cell)
+        if (cell !is null)
             return cell.ptr;
 
         return null;
@@ -715,7 +715,7 @@ public:
     size_t sizeOf(void* ptr)
     {
         auto cell = this.live_list.find(ptr);
-        if (cell)
+        if (cell !is null)
             return cell.capacity;
         return 0;
     }
@@ -734,7 +734,7 @@ public:
         BlkInfo blk_info;
 
         auto cell = this.live_list.find(ptr);
-        if (cell) {
+        if (cell !is null) {
             blk_info.base = cell.ptr;
             blk_info.size = cell.capacity;
             blk_info.attr = cell.attr;
diff --git a/gc/list.d b/gc/list.d
index 7c0af0b..f11ff2c 100644
--- a/gc/list.d
+++ b/gc/list.d
@@ -37,7 +37,7 @@ struct List
     Cell* find(bool delegate(Cell*) predicate)
     {
         auto cell = this.first;
-        while (cell) {
+        while (cell !is null) {
             if (predicate(cell))
                 return cell;
             cell = cell.next;
@@ -75,12 +75,12 @@ struct List
     {
         Cell* prev = null;
         auto cell = this.first;
-        while (cell) {
+        while (cell !is null) {
             if (predicate(cell)) {
-                if (prev)
-                    prev.next = cell.next;
-                else
+                if (prev is null)
                     this.first = cell.next;
+                else
+                    prev.next = cell.next;
                 return cell;
             }
             prev = cell;
@@ -133,7 +133,7 @@ struct List
     {
         int result = 0;
         auto cell = this.first;
-        while (cell) {
+        while (cell !is null) {
             // this is necessary to allow removing a node while iterating
             auto next = cell.next;
             result = dg(cell);
@@ -156,7 +156,7 @@ private:
     unittest // List
     {
         List l;
-        assert (l.first == null);
+        assert (l.first is null);
         assert (l.find(cast(void*) null) is null);
         assert (l.find(cast(void*) &l) is null);
         Cell[5] cells;
-- 
2.43.0