From 93a970945e8ce32cc26b47d7bb196c9a01295242 Mon Sep 17 00:00:00 2001
From: Victor Zverovich <victor.zverovich@gmail.com>
Date: Sun, 16 Dec 2012 10:03:19 -0800
Subject: [PATCH] Improve API and make it work on older GCC.

---
 format.h       | 24 ++++++++++++++++++++----
 format_test.cc |  1 -
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/format.h b/format.h
index 316b057a..2073895c 100644
--- a/format.h
+++ b/format.h
@@ -349,6 +349,16 @@ class ArgInserter {
 
   void ResetFormatter() const { formatter_ = 0; }
 
+  struct Proxy {
+    Formatter *formatter;
+    explicit Proxy(Formatter *f) : formatter(f) {}
+  };
+
+  static Formatter *Format(Proxy p) {
+    p.formatter->Format();
+    return p.formatter;
+  }
+
  public:
   ~ArgInserter() {
     if (formatter_)
@@ -362,14 +372,20 @@ class ArgInserter {
     return *this;
   }
 
+  operator Proxy() {
+    Formatter *f = formatter_;
+    formatter_ = 0;
+    return Proxy(f);
+  }
+
   // Performs formatting and returns a C string with the output.
-  friend const char *c_str(const ArgInserter &af) {
-    return af.Format()->c_str();
+  friend const char *c_str(Proxy p) {
+    return Format(p)->c_str();
   }
 
   // Performs formatting and returns a std::string with the output.
-  friend std::string str(const ArgInserter &af) {
-    return af.Format()->str();
+  friend std::string str(Proxy p) {
+    return Format(p)->str();
   }
 };
 }
diff --git a/format_test.cc b/format_test.cc
index 4e7ad837..4b86bd3d 100644
--- a/format_test.cc
+++ b/format_test.cc
@@ -731,7 +731,6 @@ TEST(ActiveFormatterTest, ArgLifetime) {
   // been destroyed, but ArgInserter dtor hasn't been called yet.
   // But that's OK since the Arg's dtor takes care of this and
   // calls Format.
-  EXPECT_EQ("test", str(af));
 }
 #endif