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diff --git a/docs/tutorials/templates.html b/docs/tutorials/templates.html deleted file mode 100644 index 76822f7071d..00000000000 --- a/docs/tutorials/templates.html +++ /dev/null @@ -1,190 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> -<html> - <!-- $Id$ --> - <head> - <title>About C++ Templates</title> - </head> - - <BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F"> -<center> - <h1>About C++ Templates</h1> -</center> - - - <hr> - -When you get to server.cpp in Tutorial 2 you'll see these lines at the bottom: -<P> -<UL> -<PRE> -<font color=blue>#if defined</font> (<font color=purple>ACE_HAS_EXPLICIT_TEMPLATE_INSTANTIATION</font>) -template class ACE_Acceptor <Logging_Handler, ACE_SOCK_ACCEPTOR>; -template class ACE_Svc_Handler<ACE_SOCK_STREAM, ACE_NULL_SYNCH>; -<font color=blue>#elif defined</font> (<font color=purple>ACE_HAS_TEMPLATE_INSTANTIATION_PRAGMA</font>) -<font color=blue>#pragma</font> <font color=purple>instantiate</font> ACE_Acceptor <Logging_Handler, ACE_SOCK_ACCEPTOR> -<font color=blue>#pragma</font> <font color=purple>instantiate</font> ACE_Svc_Handler<ACE_SOCK_STREAM, ACE_NULL_SYNCH> -<font color=blue>#endif</font> <font color=red>/* ACE_HAS_EXPLICIT_TEMPLATE_INSTANTIATION */</font> -Thanks to Krishna Padmasola for providing these. -</PRE> -</UL> -<P> -What's that all about? -<P> -Well, if you've been doing ACE for more than about 30 seconds you will -have run into the joys and sorrows of C++ templates. They're really -great things that prevent the need for complex #define'd macros, -ensure type safety and do other really nifty things. One of the -problems, however, is that not all compilers can figure out what -templates you need. -<P> -Take the simple templated class: -<UL> -<PRE> - -template <class DATATYPE> -class MyTemplate -{ -public: - MyTemplate(void) - { - } - - DATATYPE data(void) - { - return data_; - } - - void data( DATATYPE _data ) - { - data_ = _data; - } - -protected: - - DATATYPE data_; -}; -</PRE> -</UL> -<P> -Now suppose you write the following code fragment: -<P> -<UL> -<PRE> -int main(int,char**) -{ - MyTemplate<int> itemp; - MyTemplate<char> ctemp; - - ... -} -</pre> -</ul> -<P> -Some compilers will take care of you and automatically generate the -equivalent classes: -<UL> -<pre> -class MyTemplate -{ -public: - MyTemplate(void) - { - } - - int data(void) - { - return data_; - } - - void data( int _data ) - { - data_ = _data; - } - -protected: - - int data_; -}; - -class MyTemplate -{ -public: - MyTemplate(void) - { - } - - char data(void) - { - return data_; - } - - void data( char _data ) - { - data_ = _data; - } - -protected: - - char data_; -}; -</pre> -</ul> -<P> -On the other hand, some compilers will complain loudly about undefined -symbols and all sorts of other things. When Clinton Carr compiled -server.cpp of Tutorial 2 on his RedHat 5.1 (gcc) system, for instance, -he was rewarded with these lovely errors: -<P> -<UL> -<PRE> -server.cpp:60: undefined reference to `ACE_Acceptor<Client_Handler, ACE_SOCK_Acceptor>::ACE_Acceptor(ACE_Reactor *)' -server.cpp:72: undefined reference to `ACE_Acceptor<Client_Handler, ACE_SOCK_Acceptor>::open(ACE_INET_Addr const &, ACE_Reactor *,int)' -server.cpp:73: undefined reference to `ACE_Acceptor<Client_Handler, ACE_SOCK_Acceptor>::~ACE_Acceptor(void)' -server.cpp:112: undefined reference to `ACE_Acceptor<Client_Handler, ACE_SOCK_Acceptor>::~ACE_Acceptor(void)' - -</PRE> -</UL> -<P> -Figuring out the correct manual instantiations is usually an -iterative and tedious process. On Linux, I generally use a version of gcc that -will do automatic instantiaion. "Normal" gcc with the Cygnus repo -patches does that as does egcs. Lately (1/99) I've been using egcs -1.1.1 with pretty good results. On our Digital Unix 4.0b system the -native compiler (CXX) has switches that will request it to also -automatically instantiate templates as needed. -<P> -The tradeoffs? -<P> -If you choose to do manual instantiation then your code will work just -about anywhere ACE will. For complex applications, it can take a -number of hours to get things right. -<P> -If you choose to let the compiler do instantiations for you then it -will perform the iterative process. That means that every compile -will be longer than without manual instantiations. -<P> -Compromise? -<P> -Yes, you can do that. You can manually instantiate some -templates and let the compiler get the rest. Some compilers will -generate output that you can then use to figure out the correct -templates. Gcc/egcs create .rpo files for each object. These files -contain mangled names that the compiler uses to figure out what to -instantiate. With c++filt and some patience, you can parse that stuff -to figure out what the compiler is instantiating for you. Note that -c++filt expects you to have a GNU-flavored C++ compiler available. -<P> -My best advice is to get a compiler that will handle the -instantiations for you. When you have some free time on your hands, -take a look at its intermediate files (if any) and start working on -manual instantiation. -<P> -For some more hints, take a look at <A HREF="../../ACE-INSTALL.html#g++">ACE-INSTALL</A> -<P> - <hr> - -Thanks to Amos Shapira for catching a number of errors here. - - </body> -</html> - |