From b520a03c57a510b978ac5ee3382b446b72107669 Mon Sep 17 00:00:00 2001
From: ridiculousfish <corydoras@ridiculousfish.com>
Date: Tue, 25 Mar 2014 12:44:21 -0700
Subject: [PATCH] Prefer swap() member function to std::swap. We were hitting
 the inefficient generic std::swap for some derived types.

---
 builtin_set_color.cpp | 5 ++---
 highlight.cpp         | 2 +-
 parse_execution.cpp   | 2 +-
 parse_tree.cpp        | 4 ++--
 4 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/builtin_set_color.cpp b/builtin_set_color.cpp
index 6e8f55b0a..0fdc1ac0b 100644
--- a/builtin_set_color.cpp
+++ b/builtin_set_color.cpp
@@ -235,9 +235,8 @@ static int builtin_set_color(parser_t &parser, wchar_t **argv)
     output_set_writer(saved_writer_func);
 
     /* Output the collected string */
-    std::string local_output;
-    std::swap(builtin_set_color_output, local_output);
-    stdout_buffer.append(str2wcstring(local_output));
+    stdout_buffer.append(str2wcstring(builtin_set_color_output));
+    builtin_set_color_output.clear();
 
     return STATUS_BUILTIN_OK;
 }
diff --git a/highlight.cpp b/highlight.cpp
index eaaec750a..87985ae6b 100644
--- a/highlight.cpp
+++ b/highlight.cpp
@@ -350,7 +350,7 @@ bool plain_statement_get_expanded_command(const wcstring &src, const parse_node_
         if (expand_one(cmd, EXPAND_SKIP_CMDSUBST | EXPAND_SKIP_VARIABLES | EXPAND_SKIP_JOBS))
         {
             /* Success, return the expanded string by reference */
-            std::swap(cmd, *out_cmd);
+            out_cmd->swap(cmd);
             result = true;
         }
     }
diff --git a/parse_execution.cpp b/parse_execution.cpp
index 15c7de5f2..9267fb79b 100644
--- a/parse_execution.cpp
+++ b/parse_execution.cpp
@@ -1090,7 +1090,7 @@ bool parse_execution_context_t::determine_io_chain(const parse_node_t &statement
 
     if (out_chain && ! errored)
     {
-        std::swap(*out_chain, result);
+        out_chain->swap(result);
     }
     return ! errored;
 }
diff --git a/parse_tree.cpp b/parse_tree.cpp
index ae8e42d02..a1de4f966 100644
--- a/parse_tree.cpp
+++ b/parse_tree.cpp
@@ -687,13 +687,13 @@ void parse_ll_t::acquire_output(parse_node_tree_t *output, parse_error_list_t *e
 {
     if (output != NULL)
     {
-        std::swap(*output, this->nodes);
+        output->swap(this->nodes);
     }
     this->nodes.clear();
 
     if (errors != NULL)
     {
-        std::swap(*errors, this->errors);
+        errors->swap(this->errors);
     }
     this->errors.clear();
     this->symbol_stack.clear();