Merge pull request #1393 from npwoods/view_container

Introduced an STL container for a view (util::view<T>), and changed opresolv to use it

src/lib/util/coretmpl.h

@@ -17,6 +17,7 @@
 #include "corealloc.h"
 
 #include <iterator>
+#include <stdexcept>
 #include <utility>
 #include <vector>
 
@@ -351,4 +352,76 @@ private:
 };
 
 
+// ======================> contiguous_sequence_wrapper
+
+namespace util {
+
+// wraps an existing sequence of values
+template<typename T>
+class contiguous_sequence_wrapper
+{
+public:
+	typedef std::ptrdiff_t difference_type;
+	typedef std::size_t size_type;
+	typedef T value_type;
+	typedef T &reference;
+	typedef const T &const_reference;
+	typedef T *pointer;
+	typedef T *iterator;
+	typedef const T *const_iterator;
+	typedef std::reverse_iterator<iterator> reverse_iterator;
+	typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+
+	contiguous_sequence_wrapper(T *ptr, std::size_t size)
+		: m_begin(ptr)
+		, m_end(ptr + size)
+	{
+	}
+
+	contiguous_sequence_wrapper(const contiguous_sequence_wrapper &that) = default;
+
+	// iteration
+	iterator begin() { return m_begin; }
+	const_iterator begin() const { return m_begin; }
+	const_iterator cbegin() const { return m_begin; }
+	iterator end() { return m_end; }
+	const_iterator end() const { return m_end; }
+	const_iterator cend() const { return m_end; }
+
+	// reverse iteration
+	reverse_iterator rbegin() { return std::reverse_iterator<iterator>(end()); }
+	const_reverse_iterator rbegin() const { return std::reverse_iterator<const_iterator>(end()); }
+	const_reverse_iterator crbegin() const { return std::reverse_iterator<const_iterator>(cend()); }
+	reverse_iterator rend() { return std::reverse_iterator<iterator>(begin()); }
+	const_reverse_iterator rend() const { return std::reverse_iterator<iterator>(begin()); }
+	const_reverse_iterator crend() const { return std::reverse_iterator<iterator>(begin()); }
+
+	// capacity
+	size_type size() const { return m_end - m_begin; }
+	size_type max_size() const { return size(); }
+	bool empty() const { return size() == 0; }
+
+	// element access
+	reference front() { return operator[](0); }
+	const_reference front() const { return operator[](0); }
+	reference back() { return operator[](size() - 1); }
+	const_reference back() const { return operator[](size() - 1); }
+	reference operator[] (size_type n) { return m_begin[n]; }
+	const_reference operator[] (size_type n) const { return m_begin[n]; }
+	reference at(size_type n) { check_in_bounds(n); return operator[](n); }
+	const_reference at(size_type n) const { check_in_bounds(n); return operator[](n); }
+
+private:
+	iterator m_begin;
+	iterator m_end;
+
+	void check_in_bounds(size_type n)
+	{
+		if (n < 0 || n >= size())
+			throw std::out_of_range("invalid contiguous_sequence_wrapper<T> subscript");
+	}
+};
+
+}; // namespace util
+
 #endif

src/lib/util/opresolv.cpp

@@ -31,11 +31,11 @@ namespace util {
 option_resolution::option_resolution(const option_guide &guide)
 {
 	// reserve space for entries
-	m_entries.reserve(guide.end() - guide.begin());
+	m_entries.reserve(guide.entries().size());
 
 	// initialize each of the entries; can't use foreach because we need to scan the
 	// ENUM_VALUE entries
-	for (auto iter = guide.begin(); iter != guide.end(); iter++)
+	for (auto iter = guide.entries().begin(); iter != guide.entries().end(); iter++)
 	{
 		// create the entry
 		m_entries.emplace_back(*iter);
@@ -49,7 +49,7 @@ option_resolution::option_resolution(const option_guide &guide)
 			auto enum_value_end = enum_value_begin;
 
 			// and identify all entries of type ENUM_VALUE
-			while (enum_value_end != guide.end() && enum_value_end->type() == option_guide::entry::option_type::ENUM_VALUE)
+			while (enum_value_end != guide.entries().end() && enum_value_end->type() == option_guide::entry::option_type::ENUM_VALUE)
 			{
 				iter++;
 				enum_value_end++;

src/lib/util/opresolv.h

@@ -45,6 +45,8 @@
 #include <vector>
 #include <string>
 
+#include "coretmpl.h"
+
 
 //**************************************************************************
 //  TYPE DEFINITIONS
@@ -118,19 +120,17 @@ public:
 	};
 
 	// methods
-	const entry *begin() const { return m_begin; }
-	const entry *end() const { return m_end; }
+	const util::contiguous_sequence_wrapper<const entry> &entries() const { return m_entries; }
 
 protected:
-	option_guide(const entry *begin, const entry *end)
-		: m_begin(begin), m_end(end)
+	option_guide(const entry *begin, size_t count)
+		: m_entries(begin, count)
 	{
 	}
 
 
 private:
-	const entry *m_begin;
-	const entry *m_end;
+	util::contiguous_sequence_wrapper<const entry> m_entries;
 };
 
 // ======================> option_guide_impl
@@ -142,7 +142,7 @@ public:
 	template<typename... T>
 	option_guide_impl(T &&... elems)
 		: std::array<option_guide::entry, Count>({ std::forward<T>(elems)... })
-		, option_guide(Count > 0 ? &(*this)[0] : nullptr, Count > 0 ? &(*this)[0] + Count : nullptr)
+		, option_guide(Count > 0 ? &(*this)[0] : nullptr, Count)
 	{
 	}
 };