From 6512d2873a5f83e3e598d384abae4437d8a4b461 Mon Sep 17 00:00:00 2001
From: artemp <artem@mapnik.org>
Date: Thu, 20 Dec 2012 16:36:16 +0000
Subject: [PATCH] + swap patch from @joto :
 http://www.remote.org/jochen/tmp/swap.patch

---
 include/mapnik/layer.hpp |  4 ++--
 src/layer.cpp            | 31 ++++++++++++++++---------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/include/mapnik/layer.hpp b/include/mapnik/layer.hpp
index 78a17441c..b38858f06 100644
--- a/include/mapnik/layer.hpp
+++ b/include/mapnik/layer.hpp
@@ -47,7 +47,7 @@ public:
           std::string const& srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs");
 
     layer(layer const& l);
-    layer& operator=(layer const& l);
+    layer& operator=(layer const& rhs);
     bool operator==(layer const& other) const;
 
     /*!
@@ -197,7 +197,7 @@ public:
     int buffer_size() const;
     ~layer();
 private:
-    void swap(const layer& other);
+    void swap(layer& other);
 
     std::string name_;
     std::string srs_;
diff --git a/src/layer.cpp b/src/layer.cpp
index 0e8539747..ca7ed9f74 100644
--- a/src/layer.cpp
+++ b/src/layer.cpp
@@ -58,7 +58,7 @@ layer::layer(const layer& rhs)
       buffer_size_(rhs.buffer_size_),
       maximum_extent_(rhs.maximum_extent_) {}
 
-layer& layer::operator=(const layer& rhs)
+layer& layer::operator=(layer const& rhs)
 {
     layer tmp(rhs);
     swap(tmp);
@@ -70,21 +70,22 @@ bool layer::operator==(layer const& other) const
     return (this == &other);
 }
 
-void layer::swap(const layer& rhs)
+void layer::swap(layer& rhs)
 {
-    name_=rhs.name_;
-    srs_ = rhs.srs_;
-    min_zoom_=rhs.min_zoom_;
-    max_zoom_=rhs.max_zoom_;
-    active_=rhs.active_;
-    queryable_=rhs.queryable_;
-    clear_label_cache_ = rhs.clear_label_cache_;
-    cache_features_ = rhs.cache_features_;
-    group_by_ = rhs.group_by_;
-    styles_=rhs.styles_;
-    ds_=rhs.ds_;
-    buffer_size_ = rhs.buffer_size_;
-    maximum_extent_ = rhs.maximum_extent_;
+    using std::swap;
+    swap(name_, rhs.name_);
+    swap(srs_, rhs.srs_);
+    swap(min_zoom_, rhs.min_zoom_);
+    swap(max_zoom_, rhs.max_zoom_);
+    swap(active_, rhs.active_);
+    swap(queryable_, rhs.queryable_);
+    swap(clear_label_cache_, rhs.clear_label_cache_);
+    swap(cache_features_, rhs.cache_features_);
+    swap(group_by_,  rhs.group_by_);
+    swap(styles_, rhs.styles_);
+    swap(ds_, rhs.ds_);
+    swap(buffer_size_, rhs.buffer_size_);
+    swap(maximum_extent_, rhs.maximum_extent_);
 }
 
 layer::~layer() {}