From d5a98758fa903eeea10f4401053d808cb64ef911 Mon Sep 17 00:00:00 2001
From: Steven Watanabe <steven@providere-consulting.com>
Date: Thu, 8 Jan 2009 16:58:48 +0000
Subject: [PATCH] Add specializations of plain_return_type_2 for std::string. 
 Fixes #781

[SVN r50516]
---
 .../detail/operator_return_type_traits.hpp    | 35 +++++++++++++++++++
 include/boost/lambda/detail/operators.hpp     | 26 +++++++-------
 2 files changed, 48 insertions(+), 13 deletions(-)

diff --git a/include/boost/lambda/detail/operator_return_type_traits.hpp b/include/boost/lambda/detail/operator_return_type_traits.hpp
index 913fa86..4f6a84f 100644
--- a/include/boost/lambda/detail/operator_return_type_traits.hpp
+++ b/include/boost/lambda/detail/operator_return_type_traits.hpp
@@ -933,6 +933,41 @@ struct plain_return_type_2<other_action<subscript_action>, const std::basic_stri
   typedef typename std::basic_string<Char, Traits, Allocator>::const_reference type;
 };
 
+template<class Char, class Traits, class Allocator> 
+struct plain_return_type_2<arithmetic_action<plus_action>,
+                           std::basic_string<Char, Traits, Allocator>,
+                           std::basic_string<Char, Traits, Allocator> > { 
+  typedef std::basic_string<Char, Traits, Allocator> type;
+};
+
+template<class Char, class Traits, class Allocator> 
+struct plain_return_type_2<arithmetic_action<plus_action>,
+                           const Char*,
+                           std::basic_string<Char, Traits, Allocator> > { 
+  typedef std::basic_string<Char, Traits, Allocator> type;
+};
+
+template<class Char, class Traits, class Allocator> 
+struct plain_return_type_2<arithmetic_action<plus_action>,
+                           std::basic_string<Char, Traits, Allocator>,
+                           const Char*> { 
+  typedef std::basic_string<Char, Traits, Allocator> type;
+};
+
+template<class Char, class Traits, class Allocator, std::size_t N> 
+struct plain_return_type_2<arithmetic_action<plus_action>,
+                           Char[N],
+                           std::basic_string<Char, Traits, Allocator> > { 
+  typedef std::basic_string<Char, Traits, Allocator> type;
+};
+
+template<class Char, class Traits, class Allocator, std::size_t N> 
+struct plain_return_type_2<arithmetic_action<plus_action>,
+                           std::basic_string<Char, Traits, Allocator>,
+                           Char[N]> { 
+  typedef std::basic_string<Char, Traits, Allocator> type;
+};
+
 
 } // namespace lambda
 } // namespace boost
diff --git a/include/boost/lambda/detail/operators.hpp b/include/boost/lambda/detail/operators.hpp
index 4fdece2..29eb106 100644
--- a/include/boost/lambda/detail/operators.hpp
+++ b/include/boost/lambda/detail/operators.hpp
@@ -258,17 +258,17 @@ operator>>(const lambda_functor<Arg>& a, Ret(&b)(ManipArg))
 #error "Multiple defines of  BOOST_LAMBDA_PTR_ARITHMETIC_E1"
 #endif
 
-#define BOOST_LAMBDA_PTR_ARITHMETIC_E1(OPER_NAME, ACTION, CONSTB)            \
+#define BOOST_LAMBDA_PTR_ARITHMETIC_E1(OPER_NAME, ACTION, CONSTB)           \
 template<class Arg, int N, class B>                                         \
 inline const                                                                \
 lambda_functor<                                                             \
-  lambda_functor_base<ACTION, tuple<lambda_functor<Arg>, CONSTB(&)[N]> >   \
+  lambda_functor_base<ACTION, tuple<lambda_functor<Arg>, CONSTB(&)[N]> >    \
 >                                                                           \
-OPER_NAME (const lambda_functor<Arg>& a, CONSTB(&b)[N])                    \
+OPER_NAME (const lambda_functor<Arg>& a, CONSTB(&b)[N])                     \
 {                                                                           \
-  return lambda_functor<                                                    \
-    lambda_functor_base<ACTION, tuple<lambda_functor<Arg>, CONSTB(&)[N]> > \
-  >(tuple<lambda_functor<Arg>, CONSTB(&)[N]>(a, b));                       \
+  return                                                                    \
+    lambda_functor_base<ACTION, tuple<lambda_functor<Arg>, CONSTB(&)[N]> >  \
+  (tuple<lambda_functor<Arg>, CONSTB(&)[N]>(a, b));                         \
 }
 
 
@@ -276,15 +276,15 @@ OPER_NAME (const lambda_functor<Arg>& a, CONSTB(&b)[N])                    \
 #error "Multiple defines of  BOOST_LAMBDA_PTR_ARITHMETIC_E2"
 #endif
 
-#define BOOST_LAMBDA_PTR_ARITHMETIC_E2(OPER_NAME, ACTION, CONSTA)             \
-template<int N, class A, class Arg>                                          \
-inline const                                                                 \
-lambda_functor<                                                              \
+#define BOOST_LAMBDA_PTR_ARITHMETIC_E2(OPER_NAME, ACTION, CONSTA)           \
+template<int N, class A, class Arg>                                         \
+inline const                                                                \
+lambda_functor<                                                             \
   lambda_functor_base<ACTION, tuple<CONSTA(&)[N], lambda_functor<Arg> > >   \
->                                                                            \
+>                                                                           \
 OPER_NAME (CONSTA(&a)[N], const lambda_functor<Arg>& b)                     \
-{                                                                            \
-  return                                                                     \
+{                                                                           \
+  return                                                                    \
     lambda_functor_base<ACTION, tuple<CONSTA(&)[N], lambda_functor<Arg> > > \
     (tuple<CONSTA(&)[N], lambda_functor<Arg> >(a, b));                      \
 }