IVGCVSW-5433 Remove boost::transform_iterator and make_transform_iterator

Signed-off-by: Finn Williams <Finn.Williams@arm.com>
Change-Id: I28aace7092cff5743353df1b1de8e7a4691554d3

1 files changed, 82 insertions, 0 deletions

diff --git a/include/armnn/utility/TransformIterator.hpp b/include/armnn/utility/TransformIterator.hpp
new file mode 100644
index 0000000000..d4f32c5d8a
--- /dev/null
+++ b/include/armnn/utility/TransformIterator.hpp
@@ -0,0 +1,82 @@
+//
+// Copyright © 2020 Arm Ltd and Contributors. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+#pragma once
+
+#include <iterator>
+
+namespace armnn
+{
+
+template<typename Function,
+        typename Iterator,
+        typename Category = typename std::iterator_traits<Iterator>::iterator_category,
+        typename T = typename std::iterator_traits<Iterator>::value_type,
+        typename Distance = typename std::iterator_traits<Iterator>::difference_type,
+        typename Pointer = typename std::iterator_traits<Iterator>::pointer,
+        typename Reference =
+        typename std::result_of<const Function(typename std::iterator_traits<Iterator>::reference)>::type
+>
+class TransformIterator : public std::iterator<Category, T, Distance, Pointer, Reference>
+{
+
+public:
+
+    TransformIterator() = default;
+    TransformIterator(TransformIterator const& transformIterator) = default;
+    TransformIterator(TransformIterator&& transformIterator) = default;
+
+    TransformIterator(Iterator& it, Function fn) : m_it(it), m_fn(fn) {}
+    TransformIterator(Iterator&& it, Function fn) : m_it(it), m_fn(fn) {}
+
+    ~TransformIterator() = default;
+
+    TransformIterator operator=(TransformIterator const& transformIterator)
+    {
+        return{ transformIterator.it, transformIterator.fn};
+    }
+
+    TransformIterator operator=(TransformIterator&& transformIterator)
+    {
+        return{ transformIterator.it, transformIterator.fn};
+    }
+
+    TransformIterator operator++() {++m_it; return *this;}
+    TransformIterator operator--() {--m_it; return *this;}
+
+    TransformIterator operator++() const {++m_it; return *this;}
+    TransformIterator operator--() const {--m_it; return *this;}
+
+    TransformIterator operator++(int n) const {m_it += n; return *this;}
+    TransformIterator operator--(int n) const {m_it -= n; return *this;}
+
+    TransformIterator operator[](Distance n) const {m_it[n]; return  *this;};
+
+    Distance operator-(const TransformIterator& other) {return m_it - other.m_it;}
+
+    TransformIterator operator-(const Distance n) {return {m_it - n, m_fn};}
+    TransformIterator operator+(const Distance n) {return {m_it + n, m_fn};}
+
+    bool operator>(const TransformIterator& rhs) const {return m_it > rhs.m_it;}
+    bool operator<(const TransformIterator& rhs) const {return m_it < rhs.m_it;}
+    bool operator>=(const TransformIterator& rhs) const {return m_it >= rhs.m_it;}
+    bool operator<=(const TransformIterator& rhs) const {return m_it <= rhs.m_it;}
+
+    bool operator==(TransformIterator other) const {return (m_it == other.m_it);}
+    bool operator!=(TransformIterator other) const {return !(m_it == other.m_it);}
+
+    Reference operator*() const {return m_fn(*m_it);}
+
+private:
+    Iterator m_it;
+    const Function m_fn;
+};
+
+template<typename Function, typename Iterator>
+constexpr TransformIterator<Function, Iterator> MakeTransformIterator(Iterator i, Function f)
+{
+    return TransformIterator<Function, Iterator>(i, f);
+}
+
+}
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