From ce06c25e93183282be42ab79bfed2ab7c02791ec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?louiz=E2=80=99?= <louiz@louiz.org>
Date: Thu, 20 Oct 2016 19:32:20 +0200
Subject: Very little optimization by using a simpler scope_guard when possible
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The version with the vector, that can be disabled etc, is “very” slow, so we
use unique_ptr when we don’t need to disable it, and when it only contains
one function
---
 louloulibs/utils/encoding.cpp   | 8 ++++----
 louloulibs/utils/scopeguard.hpp | 7 +++++++
 2 files changed, 11 insertions(+), 4 deletions(-)

(limited to 'louloulibs/utils')

diff --git a/louloulibs/utils/encoding.cpp b/louloulibs/utils/encoding.cpp
index 507f38a..4b20797 100644
--- a/louloulibs/utils/encoding.cpp
+++ b/louloulibs/utils/encoding.cpp
@@ -76,7 +76,7 @@ namespace utils
   {
     // The given string MUST be a valid utf-8 string
     unsigned char* res = new unsigned char[original.size()];
-    ScopeGuard sg([&res]() { delete[] res;});
+    const auto sg = utils::make_scope_guard([&res](auto&&) { delete[] res;});
 
     // pointer where we write valid chars
     unsigned char* r = res;
@@ -140,7 +140,7 @@ namespace utils
         else
           throw std::runtime_error("Invalid UTF-8 passed to remove_invalid_xml_chars");
       }
-    return std::string(reinterpret_cast<char*>(res), r-res);
+    return {reinterpret_cast<char*>(res), static_cast<size_t>(r-res)};
   }
 
   std::string convert_to_utf8(const std::string& str, const char* charset)
@@ -152,7 +152,7 @@ namespace utils
       throw std::runtime_error("Cannot convert into UTF-8");
 
     // Make sure cd is always closed when we leave this function
-    ScopeGuard sg([&]{ iconv_close(cd); });
+    const auto sg = utils::make_scope_guard([&](auto&&){ iconv_close(cd); });
 
     size_t inbytesleft = str.size();
 
@@ -169,7 +169,7 @@ namespace utils
     char* outbuf_ptr = outbuf;
 
     // Make sure outbuf is always deleted when we leave this function
-    sg.add_callback([&]{ delete[] outbuf; });
+    const auto sg2 = utils::make_scope_guard([&](auto&&){ delete[] outbuf; });
 
     bool done = false;
     while (done == false)
diff --git a/louloulibs/utils/scopeguard.hpp b/louloulibs/utils/scopeguard.hpp
index ee1e2ef..cd0e89e 100644
--- a/louloulibs/utils/scopeguard.hpp
+++ b/louloulibs/utils/scopeguard.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <functional>
+#include <memory>
 #include <vector>
 
 /**
@@ -85,5 +86,11 @@ private:
 
 };
 
+template<typename F>
+auto make_scope_guard(F&& f)
+{
+  return std::unique_ptr<void, std::decay_t<F>>{(void*)1, std::forward<F>(f)};
+}
+
 }
 
-- 
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