From 50700c107fcde9d82e04c3fb86ffac299121bff2 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Thu, 27 Jun 2019 14:50:22 +0200
Subject: [PATCH] AK: Get rid of ConstVectorIterator.

We can achieve the same with just a VectorIterator<const Vector, const T>.
---
 AK/NonnullRefPtrVector.h |  2 +-
 AK/Tests/.gitignore      |  3 +++
 AK/Tests/Makefile        |  5 ++++-
 AK/Tests/TestVector.cpp  | 45 ++++++++++++++++++++++++++++++++++++++++
 AK/Vector.h              | 41 +-----------------------------------
 5 files changed, 54 insertions(+), 42 deletions(-)
 create mode 100644 AK/Tests/TestVector.cpp

diff --git a/AK/NonnullRefPtrVector.h b/AK/NonnullRefPtrVector.h
index 151863fe836be4..f5e438f3de9443 100644
--- a/AK/NonnullRefPtrVector.h
+++ b/AK/NonnullRefPtrVector.h
@@ -29,7 +29,7 @@ class NonnullRefPtrVector : public Vector<NonnullRefPtr<T>, inline_capacity> {
     Iterator begin() { return Iterator(*this, 0); }
     Iterator end() { return Iterator(*this, size()); }
 
-    using ConstIterator = ConstVectorIterator<NonnullRefPtrVector, T>;
+    using ConstIterator = VectorIterator<const NonnullRefPtrVector, const T>;
     ConstIterator begin() const { return ConstIterator(*this, 0); }
     ConstIterator end() const { return ConstIterator(*this, size()); }
 
diff --git a/AK/Tests/.gitignore b/AK/Tests/.gitignore
index 2e42a5a41ccabc..3e8c653d02feb8 100644
--- a/AK/Tests/.gitignore
+++ b/AK/Tests/.gitignore
@@ -1,2 +1,5 @@
 TestString
 TestQueue
+TestVector
+*.d
+*.o
diff --git a/AK/Tests/Makefile b/AK/Tests/Makefile
index dd7fc4a8e87433..1a87af2faa1e16 100644
--- a/AK/Tests/Makefile
+++ b/AK/Tests/Makefile
@@ -1,4 +1,4 @@
-all: TestString TestQueue
+all: TestString TestQueue TestVector
 
 CXXFLAGS = -std=c++17 -Wall -Wextra
 
@@ -8,5 +8,8 @@ TestString: TestString.cpp ../String.cpp ../StringImpl.cpp ../StringBuilder.cpp
 TestQueue: TestQueue.cpp ../String.cpp ../StringImpl.cpp ../StringBuilder.cpp ../StringView.cpp TestHelpers.h
 	$(CXX) $(CXXFLAGS) -I../ -I../../ -o $@ TestQueue.cpp ../String.cpp ../StringImpl.cpp ../StringBuilder.cpp ../StringView.cpp
 
+TestVector: TestVector.cpp ../String.cpp ../StringImpl.cpp ../StringBuilder.cpp ../StringView.cpp TestHelpers.h
+	$(CXX) $(CXXFLAGS) -I../ -I../../ -o $@ TestVector.cpp ../String.cpp ../StringImpl.cpp ../StringBuilder.cpp ../StringView.cpp
+
 clean:
 	rm -f TestString TestQueue
diff --git a/AK/Tests/TestVector.cpp b/AK/Tests/TestVector.cpp
new file mode 100644
index 00000000000000..182a3acbe46a24
--- /dev/null
+++ b/AK/Tests/TestVector.cpp
@@ -0,0 +1,45 @@
+#include "TestHelpers.h"
+#include <AK/AKString.h>
+#include <AK/Vector.h>
+
+int main()
+{
+    EXPECT(Vector<int>().is_empty());
+    EXPECT(Vector<int>().size() == 0);
+
+    Vector<int> ints;
+    ints.append(1);
+    ints.append(2);
+    ints.append(3);
+    EXPECT_EQ(ints.size(), 3);
+    EXPECT_EQ(ints.take_last(), 3);
+    EXPECT_EQ(ints.size(), 2);
+    EXPECT_EQ(ints.take_last(), 2);
+    EXPECT_EQ(ints.size(), 1);
+    EXPECT_EQ(ints.take_last(), 1);
+    EXPECT_EQ(ints.size(), 0);
+
+    ints.clear();
+    EXPECT_EQ(ints.size(), 0);
+
+    Vector<String> strings;
+    strings.append("ABC");
+    strings.append("DEF");
+
+    int loop_counter = 0;
+    for (const String& string : strings) {
+        EXPECT(!string.is_null());
+        EXPECT(!string.is_empty());
+        ++loop_counter;
+    }
+
+    loop_counter = 0;
+    for (auto& string : (const_cast<const Vector<String>&>(strings))) {
+        EXPECT(!string.is_null());
+        EXPECT(!string.is_empty());
+        ++loop_counter;
+    }
+    EXPECT_EQ(loop_counter, 2);
+
+    return 0;
+}
diff --git a/AK/Vector.h b/AK/Vector.h
index 559eaa8500eaf8..e639ba6c1e0995 100644
--- a/AK/Vector.h
+++ b/AK/Vector.h
@@ -51,45 +51,6 @@ class VectorIterator {
     int m_index { 0 };
 };
 
-template<typename VectorType, typename ElementType>
-class ConstVectorIterator {
-public:
-    bool operator!=(const ConstVectorIterator& other) { return m_index != other.m_index; }
-    bool operator==(const ConstVectorIterator& other) { return m_index == other.m_index; }
-    bool operator<(const ConstVectorIterator& other) { return m_index < other.m_index; }
-    bool operator>(const ConstVectorIterator& other) { return m_index > other.m_index; }
-    bool operator>=(const ConstVectorIterator& other) { return m_index >= other.m_index; }
-    ConstVectorIterator& operator++()
-    {
-        ++m_index;
-        return *this;
-    }
-    ConstVectorIterator& operator--()
-    {
-        --m_index;
-        return *this;
-    }
-    ConstVectorIterator operator-(int value) { return { m_vector, m_index - value }; }
-    ConstVectorIterator operator+(int value) { return { m_vector, m_index + value }; }
-    ConstVectorIterator& operator=(const ConstVectorIterator& other)
-    {
-        m_index = other.m_index;
-        return *this;
-    }
-    const ElementType& operator*() const { return m_vector[m_index]; }
-    int operator-(const ConstVectorIterator& other) { return m_index - other.m_index; }
-
-private:
-    friend VectorType;
-    ConstVectorIterator(const VectorType& vector, const int index)
-        : m_vector(vector)
-        , m_index(index)
-    {
-    }
-    const VectorType& m_vector;
-    int m_index { 0 };
-};
-
 template<typename T, int inline_capacity = 0>
 class Vector {
 public:
@@ -416,7 +377,7 @@ class Vector {
     Iterator begin() { return Iterator(*this, 0); }
     Iterator end() { return Iterator(*this, size()); }
 
-    using ConstIterator = ConstVectorIterator<Vector, T>;
+    using ConstIterator = VectorIterator<const Vector, const T>;
     ConstIterator begin() const { return ConstIterator(*this, 0); }
     ConstIterator end() const { return ConstIterator(*this, size()); }