add -, + and [] to child config iterators.

wesnoth · Jul 6, 2015 · 70a83ba · 70a83ba
1 parent b1dac5d
commit 70a83ba
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/src/config.hpp b/src/config.hpp
@@ -126,6 +126,7 @@ class config
 		typedef config *pointer;
 		typedef config &reference;
 		typedef child_list::iterator Itor;
+		typedef child_iterator this_type;
 		explicit child_iterator(const Itor &i): i_(i) {}
 
 		child_iterator &operator++() { ++i_; return *this; }
@@ -139,6 +140,11 @@ class config
 		bool operator==(const child_iterator &i) const { return i_ == i.i_; }
 		bool operator!=(const child_iterator &i) const { return i_ != i.i_; }
 
+		config &operator[](Itor::difference_type n) const { return *i_[n]; }
+		friend Itor::difference_type operator-(const this_type& a, const this_type& b) { return a.i_ - b.i_; }
+		friend this_type operator-(const this_type& a, Itor::difference_type n) { return this_type(a.i_ - n); }
+		friend this_type operator+(const this_type& a, Itor::difference_type n) { return this_type(a.i_ + n); }
+		friend this_type operator+(Itor::difference_type n, const this_type& a) { return this_type(a.i_ + n); }
 	private:
 		Itor i_;
 		friend struct const_child_iterator;
@@ -152,6 +158,7 @@ class config
 		typedef const config *pointer;
 		typedef const config &reference;
 		typedef child_list::const_iterator Itor;
+		typedef const_child_iterator this_type;
 		explicit const_child_iterator(const Itor &i): i_(i) {}
 		const_child_iterator(const child_iterator &i): i_(i.i_) {}
 
@@ -166,6 +173,11 @@ class config
 		bool operator==(const const_child_iterator &i) const { return i_ == i.i_; }
 		bool operator!=(const const_child_iterator &i) const { return i_ != i.i_; }
 
+		const config &operator[](Itor::difference_type n) const { return *i_[n]; }
+		friend Itor::difference_type operator-(const this_type& a, const this_type& b) { return a.i_ - b.i_; }
+		friend this_type operator-(const this_type& a, Itor::difference_type n) { return this_type(a.i_ - n); }
+		friend this_type operator+(const this_type& a, Itor::difference_type n) { return this_type(a.i_ + n); }
+		friend this_type operator+(Itor::difference_type n, const this_type& a) { return this_type(a.i_ + n); }
 	private:
 		Itor i_;
 	};