From e531e7ce2e50cb1c70d399a41acaed0bcf5423f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jaakko=20J=C3=A4rvi?= <jarvi@cs.tamu.edu>
Date: Mon, 5 Nov 2001 21:18:48 +0000
Subject: [PATCH] added a comment about performance penalties with some
 compilers

[SVN r11603]
---
 doc/tuple_users_guide.html | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/doc/tuple_users_guide.html b/doc/tuple_users_guide.html
index 21d396a..992b77a 100644
--- a/doc/tuple_users_guide.html
+++ b/doc/tuple_users_guide.html
@@ -416,8 +416,9 @@ parseable.
 
 <h2><a name = "performance">Performance</a></h2>
 
-Tuples are efficient. All functions are small inlined one-liners and a decent compiler will eliminate any extra cost. 
-Particularly, there is no performance difference between this code:
+All tuple access and construction functions are small inlined one-liners. 
+Therefore, a decent compiler can eliminate any extra cost of using tuples compared to using hand written tuple like classes. 
+Particularly, with a decent compiler there is no performance difference between this code:
 
 <pre><code>class hand_made_tuple { 
   A a; B b; C c;
@@ -439,6 +440,8 @@ and this code:
 t.get&lt;0&gt;(); t.get&lt;1&gt;(); t.get&lt;2&gt;(); 
 </code></pre>
 
+<p>Note, that there are widely used compilers (e.g. bcc 5.5.1) which fail to optimize this kind of tuple usage.
+</p>  
 <p>
 Depending on the optimizing ability of the compiler, the tier mechanism may have a small performance penalty compared to using
 non-const reference parameters as a mechanism for returning multiple values from a function.