From f7dcf3f0be55316bf20ac0c318dd90cb78a75c80 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 22 May 2013 16:14:16 +0300
Subject: [PATCH] Rewrite composite shape vector constructors with iterator
 ranges

Besides the issue of favoring one container type over others, constness
of the contents causes it to be a different, incompatible type.  Iterators
solve this in an elegant way.
---
 source/geometry/compositeshape.h | 23 +++++++++++++++++------
 source/geometry/intersection.h   | 22 +++++++++++++++-------
 source/geometry/union.h          | 18 +++++++++++++-----
 3 files changed, 45 insertions(+), 18 deletions(-)

diff --git a/source/geometry/compositeshape.h b/source/geometry/compositeshape.h
index 9476f99..50075d9 100644
--- a/source/geometry/compositeshape.h
+++ b/source/geometry/compositeshape.h
@@ -1,6 +1,7 @@
 #ifndef MSP_GEOMETRY_COMPOSITESHAPE_H_
 #define MSP_GEOMETRY_COMPOSITESHAPE_H_
 
+#include <stdexcept>
 #include <vector>
 #include "shape.h"
 
@@ -19,10 +20,12 @@ protected:
 
 	ShapeArray shapes;
 
+	CompositeShape() { }
 	CompositeShape(const Shape<T, D> &, const Shape<T, D> &);
-	CompositeShape(const ShapeArray &);
 	CompositeShape(const CompositeShape &);
 	CompositeShape &operator=(const CompositeShape &);
+	template<typename Iter>
+	void init_from_iter_range(const Iter &, const Iter &);
 public:
 	virtual ~CompositeShape();
 
@@ -41,13 +44,21 @@ inline CompositeShape<T, D, O>::CompositeShape(const Shape<T, D> &s1, const Shap
 }
 
 template<typename T, unsigned D, typename O>
-inline CompositeShape<T, D, O>::CompositeShape(const ShapeArray &s)
+template<typename Iter>
+inline void CompositeShape<T, D, O>::init_from_iter_range(const Iter &begin, const Iter &end)
 {
-	if(s.empty())
-		throw std::invalid_argument("CompositeShape::CompositeShape");
+	if(begin==end)
+		throw std::invalid_argument("CompositeShape::init_from_iter_range");
 
-	shapes.reserve(s.size());
-	for(typename ShapeArray::const_iterator i=s.begin(); i!=s.end(); ++i)
+	for(Iter i=begin; i!=end; ++i)
+		shapes.push_back((*i)->clone());
+}
+
+template<typename T, unsigned D, typename O>
+inline CompositeShape<T, D, O>::CompositeShape(const CompositeShape<T, D, O> &other)
+{
+	shapes.reserve(other.shapes.size());
+	for(typename ShapeArray::const_iterator i=other.shapes.begin(); i!=other.shapes.end(); ++i)
 		shapes.push_back((*i)->clone());
 }
 
diff --git a/source/geometry/intersection.h b/source/geometry/intersection.h
index 53c25c2..c20aae1 100644
--- a/source/geometry/intersection.h
+++ b/source/geometry/intersection.h
@@ -23,27 +23,35 @@ struct IntersectionOps
 template<typename T, unsigned D>
 class Intersection: public CompositeShape<T, D, IntersectionOps<T, D> >
 {
+private:
+	Intersection() { }
 public:
 	Intersection(const Shape<T, D> &, const Shape<T, D> &);
-	Intersection(const std::vector<Shape<T, D> *> &);
+
+	template<typename Iter>
+	static Intersection from_iterator_range(const Iter &, const Iter &);
 
 	virtual Intersection *clone() const;
 };
 
 template<typename T, unsigned D>
-Intersection<T, D>::Intersection(const Shape<T, D> &s1, const Shape<T, D> &s2):
+inline Intersection<T, D>::Intersection(const Shape<T, D> &s1, const Shape<T, D> &s2):
 	CompositeShape<T, D, IntersectionOps<T, D> >(s1, s2)
 { }
 
 template<typename T, unsigned D>
-Intersection<T, D>::Intersection(const std::vector<Shape<T, D> *> &s):
-	CompositeShape<T, D, IntersectionOps<T, D> >(s)
-{ }
+template<typename Iter>
+inline Intersection<T, D> Intersection<T, D>::from_iterator_range(const Iter &begin, const Iter &end)
+{
+	Intersection<T, D> shape;
+	shape.init_from_iter_range(begin, end);
+	return shape;
+}
 
 template<typename T, unsigned D>
-Intersection<T, D> *Intersection<T, D>::clone() const
+inline Intersection<T, D> *Intersection<T, D>::clone() const
 {
-	return new Intersection<T, D>(this->shapes);
+	return new Intersection<T, D>(*this);
 }
 
 
diff --git a/source/geometry/union.h b/source/geometry/union.h
index fadeff2..13eb708 100644
--- a/source/geometry/union.h
+++ b/source/geometry/union.h
@@ -23,9 +23,13 @@ struct UnionOps
 template<typename T, unsigned D>
 class Union: public CompositeShape<T, D, UnionOps<T, D> >
 {
+private:
+	Union() { }
 public:
 	Union(const Shape<T, D> &, const Shape<T, D> &);
-	Union(const std::vector<Shape<T, D> *> &);
+
+	template<typename Iter>
+	static Union from_iterator_range(const Iter &, const Iter &);
 
 	virtual Union *clone() const;
 };
@@ -36,14 +40,18 @@ inline Union<T, D>::Union(const Shape<T, D> &s1, const Shape<T, D> &s2):
 { }
 
 template<typename T, unsigned D>
-inline Union<T, D>::Union(const std::vector<Shape<T, D> *> &s):
-	CompositeShape<T, D, UnionOps<T, D> >(s)
-{ }
+template<typename Iter>
+inline Union<T, D> Union<T, D>::from_iterator_range(const Iter &begin, const Iter &end)
+{
+	Union<T, D> shape;
+	shape.init_from_iter_range(begin, end);
+	return shape;
+}
 
 template<typename T, unsigned D>
 inline Union<T, D> *Union<T, D>::clone() const
 {
-	return new Union<T, D>(this->shapes);
+	return new Union<T, D>(*this);
 }
 
 
-- 
2.43.0