From fc49d33c8d17dd6c5e3de6f23024d1d4fa98e920 Mon Sep 17 00:00:00 2001
From: Roman Donchenko <roman.donchenko@itseez.com>
Date: Thu, 21 Nov 2013 18:26:38 +0400
Subject: [PATCH] Gave cv::String appropriate += operators.

Note that since String is a reference to an immutable string,
this doesn't actually change the string; it just replaces *this
with a reference to the concatenated string.
---
 modules/core/include/opencv2/core/cvstd.hpp   | 26 +++++++++++++++++++
 .../core/include/opencv2/core/cvstd.inl.hpp   |  7 +++++
 2 files changed, 33 insertions(+)

diff --git a/modules/core/include/opencv2/core/cvstd.hpp b/modules/core/include/opencv2/core/cvstd.hpp
index afdeb2549a..f15e6a9351 100644
--- a/modules/core/include/opencv2/core/cvstd.hpp
+++ b/modules/core/include/opencv2/core/cvstd.hpp
@@ -364,6 +364,10 @@ public:
     String& operator=(const char* s);
     String& operator=(char c);
 
+    String& operator+=(const String& str);
+    String& operator+=(const char* s);
+    String& operator+=(char c);
+
     size_t size() const;
     size_t length() const;
 
@@ -416,6 +420,7 @@ public:
     String(const std::string& str);
     String(const std::string& str, size_t pos, size_t len = npos);
     String& operator=(const std::string& str);
+    String& operator+=(const std::string& str);
     operator std::string() const;
 
     friend String operator+ (const String& lhs, const std::string& rhs);
@@ -544,6 +549,27 @@ String& String::operator=(char c)
     return *this;
 }
 
+inline
+String& String::operator+=(const String& str)
+{
+    *this = *this + str;
+    return *this;
+}
+
+inline
+String& String::operator+=(const char* s)
+{
+    *this = *this + s;
+    return *this;
+}
+
+inline
+String& String::operator+=(char c)
+{
+    *this = *this + c;
+    return *this;
+}
+
 inline
 size_t String::size() const
 {
diff --git a/modules/core/include/opencv2/core/cvstd.inl.hpp b/modules/core/include/opencv2/core/cvstd.inl.hpp
index 8642b7442e..ce18da30a3 100644
--- a/modules/core/include/opencv2/core/cvstd.inl.hpp
+++ b/modules/core/include/opencv2/core/cvstd.inl.hpp
@@ -103,6 +103,13 @@ String& String::operator = (const std::string& str)
     return *this;
 }
 
+inline
+String& String::operator += (const std::string& str)
+{
+    *this = *this + str;
+    return *this;
+}
+
 inline
 String::operator std::string() const
 {