(setq-default indent-tabs-mode nil)Microsoft Visual C++ users should do the following:
        Choose:  Tools -- Options -- Tabs
        Then Set:  "Tab size" to 8 and "Indent size" to 2, and
        indent using spaces.
        
(setq-default nuke-trailing-whitespace-p t)
MakeProjectCreator,
        tao_idl do not also go beyond that limit. Some operating
        systems cannot handle very long file names correctly.
-? command line argument, are
        provided to the program.
main can take any of the
        three forms:
        
        int main (int argc, char *argv[])
        int wmain (int argc, wchar_t *argv[])
        int ACE_TMAIN (int argc, ACE_TCHAR *argv[])
        
        Of them, the entry point main always gives you
        the command line argument in char strings form.  The entry
        point wmain currently can only be used under
        Win32 and it returns the command line arguments in wchar
        strings format.  Defining the ACE_TMAIN as the
        program entry point is the more portable form.  The command
        line arguments are given in char strings in most cases,
        or wchar strings when ACE_USES_WCHAR is defined.
        See $ACE_ROOT/docs/wchar.txt for more information
        on ACE support on wchar.
    
        int
        ACE_TMAIN (int argc, ACE_TCHAR *argv[])
        {
          [...]
          return 0;
        }
        
        If you don't use the argc and/or argv
        arguments, don't declare them, e.g.,
        
        int
        ACE_TMAIN (int, ACE_TCHAR *[])
        {
          [...]
          return 0;
        }
        
        Please declare the second argument as ACE_TCHAR *[]
        instead of ACE_TCHAR ** or char *[].
        Ancient versions of MSC++
        complained about ACE_TCHAR ** and char
        *[] is not Unicode-compliant.
        main must also return 0 on successful
        termination, and non-zero otherwise.
float and
            double) and operations
        unless absolutely necessary.  Not all ACE platforms support them.
        Therefore, wherever they are used, ACE_LACKS_FLOATING_POINT
        conditional code must be also be used.
Error" in a source
            code filename. GNU Make's error messages start with
            "Error".  So, it's much easier to search for
            errors if filenames don't contain "Error".
        // $Id$
        
        It is not necessary to fill in the fields of the keyword string,
        or modify them when you edit a file that already has one.  CVS
        does that automatically when you checkout or update the file.To insert that string at the top of a file:
        perl -pi -e \
          'if (! $o) {printf "// \$Id\$\n\n";}; $o = 1;' file
        
#endif
        with a /*  */ C-style comment.  It
        should correspond to the condition in the matching
        #if directive.  For example,
        
        #if defined (ACE_HAS_THREADS)
        # if defined (ACE_HAS_STHREADS)
        #   include /**/ <synch.h>
        #   include /**/ <thread.h>
        #   define ACE_SCOPE_PROCESS P_PID
        #   define ACE_SCOPE_LWP P_LWPID
        #   define ACE_SCOPE_THREAD (ACE_SCOPE_LWP + 1)
        # else
        #   define ACE_SCOPE_PROCESS 0
        #   define ACE_SCOPE_LWP 1
        #   define ACE_SCOPE_THREAD 2
        # endif /* ACE_HAS_STHREADS */
        #endif /* ACE_HAS_THREADS */
        
char * /* foo */ instead of
        char */*foo*/.  MS VC++
        complains otherwise.
/**/ between an
        #include and
        filename, for system headers and
        ace/pre.h and
        ace/post.h as
        shown in the above example.  This avoids dependency problems
        with Visual C++ and prevents Doxygen from including the
        headers in the file reference trees.  
enum values, and variables
        It's always best to prefix them with something like ACE_
        or TAO_.  There are too many system headers out
        there that #define OK, SUCCESS,
        ERROR, index, s_type,
        and so on.
defined(macro) before specifying
      the expression.  For example:
#if __FreeBSD__ < 3will evaluate true on any platform where
__FreeBSD__ is
not defined.  The correct way to write that guard is:
#if defined (__FreeBSD__) && __FreeBSD__ < 3
#ifdefs with typedefs
        and #defines.  For example, use this:
        
        #if defined(ACE_PSOS)
          typedef long ACE_NETIF_TYPE;
        # define ACE_DEFAULT_NETIF 0
        #else  /* ! ACE_PSOS */
          typedef const TCHAR* ACE_NETIF_TYPE;
        # define ACE_DEFAULT_NETIF ASYS_TEXT("le0")
        #endif /* ! ACE_PSOS */
        instead of:
#if defined (ACE_PSOS) // pSOS supports numbers, not names for network interfaces long net_if, #else /* ! ACE_PSOS */ const TCHAR *net_if, #endif /* ! ACE_PSOS */
        #ifndef FOO_H
        #define FOO_H
        [contents of header file]
        #endif /* FOO_H */
        
        This exact construct (note the #ifndef)
        is optimized by many compilers such they only open the
        file once per compilation unit.  Thanks to Eric C. Newton
        <ecn@smart.net> for pointing that out.
        If the header #includes an ACE library header,
        then it's a good idea to include the #pragma once
        directive:
        
        #ifndef FOO_H
        #define FOO_H
        #include "ace/ACE.h"
        #if !defined (ACE_LACKS_PRAGMA_ONCE)
        # pragma once
        #endif /* ACE_LACKS_PRAGMA_ONCE */
        [contents of header file]
        #endif /* FOO_H */
        
        #pragma once must be protected, because some
        compilers complain about it.  The protection depends on
        ACE_LACKS_PRAGMA_ONCE, which is defined in
        some ACE config headers.  Therefore, the protected
        #pragma once construct should only be used after
        an #include of an ACE library header.  Note that
        many compilers enable the optimization if the #ifndef
        protection construct is used, so for them, #pragma once
        is superfluous.
        No code can appear after the final
        #endif for the optimization to be effective and
        correct.
Files that contain parametric classes should follow this style:
      #ifndef FOO_T_H
      #define FOO_T_H
      #include "ace/ACE.h"
      #if !defined (ACE_LACKS_PRAGMA_ONCE)
      # pragma once
      #endif /* ACE_LACKS_PRAGMA_ONCE */
      // Put your template declarations here...
      #if defined (__ACE_INLINE__)
      #include "Foo_T.inl"
      #endif /* __ACE_INLINE__ */
      #if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
      #include "Foo_T.cpp"
      #endif /* ACE_TEMPLATES_REQUIRE_SOURCE */
      #if defined (ACE_TEMPLATES_REQUIRE_PRAGMA)
      #pragma implementation "Foo_T.cpp"
      #endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */
      #endif /* FOO_T_H */
      
      Notice that some compilers need to see the code of the template,
      hence the .cpp file must be included from the
      header file.
      
      To avoid multiple inclusions of the .cpp file it
      should also be protected as in:
      
      #ifndef FOO_T_CPP
      #define FOO_T_CPP
      #include "Foo_T.h"
      #if !defined (ACE_LACKS_PRAGMA_ONCE)
      # pragma once
      #endif /* ACE_LACKS_PRAGMA_ONCE */
      #if !defined (__ACE_INLINE__)
      #include "ace/Foo_T.inl"
      #endif /* __ACE_INLINE__ */
      // put your template code here
      #endif /* FOO_T_H */
      Finally, you may want to include the template header file from a
      non-template header file (check
      $ACE_ROOT/ace/Synch.h); in such a case the template
      header should be included after the inline
      function definitions, as in:
      #ifndef FOO_H
      #define FOO_H
      #include "ace/ACE.h"
      #if !defined (ACE_LACKS_PRAGMA_ONCE)
      # pragma once
      #endif /* ACE_LACKS_PRAGMA_ONCE */
      // Put your non-template declarations here...
      #if defined (__ACE_INLINE__)
      #include "Foo.inl"
      #endif /* __ACE_INLINE__ */
      #include "Foo_T.h"
      #endif /* FOO_H */
#include <math.h> if at all possible.
      The /usr/include/math.h on SunOS 5.5.1 through 5.7
      defines a struct name exception, which complicates
      use of exceptions.
.cpp file always include the corresponding
      header file first, like this:
        // This is Foo.cpp
        #include "Foo.h"
        #include "tao/Bar.h"
        #include "ace/Baz.h"
        // Here comes the Foo.cpp code....
In this way we are sure that the header file is self-contained and can be safely included from some place else.
<corba.h>, this file should only be included
      by the user and introduces cyclic dependencies in the library
      that we must avoid.
for loops should look like:
        
        for (unsigned int i = 0; i < count; ++i)
          ++total;
        
        Though, I prefer to always wrap the body of the loop in braces,
        to avoid surprises when other code or debugging statements are
        added, and to maintain sanity when the body consists of a macro,
        such as an ACE_ASSERT without a trailing semicolon:
        
        for (unsigned int i = 0; i < count; ++i)
          {
            ACE_ASSERT (++total < UINT_MAX;)
          }
        
        Similarly, if statements should have
        a space after the "if", and no spaces just after
        the opening parenthesis and just before the closing parenthesis.
        size_t i = 0;
        for (size_t j = 0; file_name [j] != '\0'; ++i, ++j)
          {
            if (file_name [j] == '\\' && file_name [j + 1] == '\\')
              ++j;
            file_name [i] = file_name [j];
          }
        // Terminate this string.
        file_name [i] = '\0';
        
Therefore, use this idiom for iterators, with prefix operator on the loop index:
       ACE_Ordered_MultiSet<int> set;
       ACE_Ordered_MultiSet_Iterator<int> iter(set);
       for (i = -10; i < 10; ++i)
         set.insert (2 * i + 1);
       
       rather than the postfix operator:
       
       for (i = -10; i < 10; i++)
         set.insert (2 * i + 1);
       
 if (...) else ....  
    instead of   ?:   operator. It is a lot
    less error prone, and will help you avoid bugs caused due to the
    precedence of   ?:  , compared with other
    operators in an expression.
    operator==, it must also provide
        operator!=.  Also, both these operators must be
        const and return bool.
    
.inl
        file.  That file is conditionally included by both the
        .h file, for example:
            class ACE_Export ACE_High_Res_Timer
            {
              [...]
            };
            #if defined (__ACE_INLINE__)
            #include "ace/High_Res_Timer.inl"
            #endif /* __ACE_INLINE__ */
            
        and .cpp file:
            #define ACE_BUILD_DLL
            #include "ace/High_Res_Timer.h"
            #if !defined (__ACE_INLINE__)
            #include "ace/High_Res_Timer.inl"
            #endif /* __ACE_INLINE__ */
            ACE_ALLOC_HOOK_DEFINE(ACE_High_Res_Timer)
            
        NOTE: It is very important to ensure than an
        inline function will not be used before its definition is seen.
        Therefore, the inline functions in the .inl file should be arranged
        properly.  Some compilers, such as g++ with the
        -Wall option, will issue warnings for violations.
ACE_INLINE
Foo::bar ()
{
  this->baz ();
}
ACE_Export must be inserted between the
        class keyword and class name for all classes that
        are exported from libraries, as shown in the example above.
        However, do not use
        ACE_Export for template classes or classes that
        are not used out of the ACE library, for example.!
        void object_addr (const ACE_INET_Addr &);
        // Sets <object_addr_> cache from <host> and <port>.
        const ACE_INET_Addr &object_addr const (void);
        // Returns the <ACE_INET_Addr> for this profile.
        instead of the "set_" and "get_" form.
delete to deallocate
        memory that was allocated with malloc.
        Similarly, never associate free with
        new.
        ACE_NEW or
        ACE_NEW_RETURN should be used to
        allocate memory, and delete should
        be used to deallocate it.  And be careful to use the correct form,
        delete or
        delete [] to correspond to the
        allocation.
ACE_NEW or
        ACE_NEW_RETURN to allocate memory,
        because they check for successful allocation and set errno
        appropriately if it fails.
int.
        On all currently supported ACE platforms, it is safe to cast
        a pointer to or from a long.
        ACE_Time_Value (long sec, long usec = 0);
        
        So, ACE_Time_Value (2.5) has the unfortunate
        effect of coercing the 2.5 to a long with value 2.  That's
        probably not what the programmer intended, and many compilers
        don't warn about it.
        A nice fix would be to add an ACE_Time_Value (double)
        constructor.  But, that would cause ambiguous overloading
        due to the default value for the second argument of
        ACE_Time_Value (long sec, long usec = 0).
        We're stuck with ACE_Time_Value, but now we
        know that it's easy to avoid.
        ssize_t n_bytes;
        // Send multicast of one byte, enough to wake up server.
        if ((n_bytes = multicast.send ((char *) &reply_port,
          sizeof reply_port)) == -1)
        
        Write it like this:
        
        ssize_t n_bytes = multicast.send ((char *) &reply_port,
          sizeof reply_port)
        // Send multicast of one byte, enough to wake up server.
        if (n_bytes == -1)
        But, beware if the initialization is of a static variable. A static variable is only initialized the first time its declaration is seen. Of course, we should avoid using static (and non-constant) variables at all.
        if (test)
          {
            // true branch
          }
        else
          {
            // false branch
          }
        is preferred over:
        if (! test)
          {
            // false test branch
          }
        else
          {
            // true test branch
          }
        
static_cast<int> (foo)) instead.
        // Disallow copying by not implementing the following . . .
        ACE_Object_Manager (const ACE_Object_Manager &);
        ACE_Object_Manager &operator= (const ACE_Object_Manager &);
        
        If the class is a template class, then the
        ACE_UNIMPLEMENTED_FUNC macro should be used:
        
        // = Disallow copying...
        ACE_UNIMPLEMENTED_FUNC (ACE_TSS (const ACE_TSS<TYPE> &))
        ACE_UNIMPLEMENTED_FUNC (void operator= (const ACE_TSS<TYPE> &))
        
        ACE_UNIMPLEMENTED_FUNC can be used with non-template
        classes as well.  Though for consistency and maximum safety, it
        should be avoided for non-template classes.
BOOL, or similar types.
            (ACE_CDR::Boolean and
            CORBA::Boolean are acceptable).  Use the
            standard C++ bool for boolean variables, instead.
-I)
        to include any directory which contains files with template
        definitions.  The Compaq Tru64 cxx -ptv compiler option
        may help diagnose missing template instantiation problems.
this->member. This makes it clear to the
        reader that a class member is being used. It also makes it crystal
        clear to the compiler which variable/function you mean in cases
        where it might make a difference.
  
ACE_DEBUG for printouts,
         and ACE_OS::fprintf () for
         file I/O.  Avoid using iostreams because of implementation
         differences across platforms.
ACE_DEBUG and
         ACE_ERROR don't support
         %ld of any other multicharacter format.
ACE_TCHAR instead of char for strings and ACE_TEXT()
         around string literals.  Exceptions are char
            arrays used for data  and strings that need to remain as 1
            byte characters.
     ACE_TCHAR,
         use the ACE_TEXT_CHAR_TO_TCHAR() macro.  If you have a ACE_TCHAR
         string that needs to be converted to a char string, use the
         ACE_TEXT_ALWAYS_CHAR() macro
     TCHAR macros.  The wide character-ness of ACE
         is separate from UNICODE and _UNICODE.
     ACE_TCHAR or ACE_TEXT.  The CORBA specification
         defines APIs as using char.  So most of the time there is no need
         to use wide characters.
  
        #include "iostream.h"
        class exe_foo
        {
        public:
          exe_foo (int data) : data_ (data)
            { cerr << "constructor of exception called" << endl; }
          ~exe_foo ()
            { cerr << "destructor of exception called" << endl; }
          exe_foo (const exe_foo& foo) : data_ (foo.data_)
            { cerr << "copy constructor of exception called"
                   << endl; }
          int data_;
        };
        void
        good (int a)
        {
          throw exe_foo (a);
        };
        void
        bad (int a)
        {
          exe_foo foo (a);
          throw foo;
        };
        int main ()
        {
          cout << endl << "First exception" << endl
               << endl;
          try
            {
              good (0);
            }
          catch (exe_foo &foo)
            {
              cerr << "exception caught: " << foo.data_
                   << endl;
            }
          cout << endl << "Second exception" << endl
               << endl;
          try
            {
              good (0);
            }
          catch (exe_foo foo)
            {
              cerr << "exception caught: " << foo.data_
                   << endl;
            }
          cout << endl << "Third exception" << endl
               << endl;
          try
            {
              bad (1);
            }
          catch (exe_foo &foo)
            {
              cerr << "exception caught: " << foo.data_
                   << endl;
            }
          cout << endl << "Fourth exception" << endl
               << endl;
          try
            {
              bad (1);
            }
          catch (exe_foo foo)
            {
              cerr << "exception caught: " << foo.data_
                   << endl;
            }
          return 0;
        }
        
     Output is: 
        First exception
        constructor of exception called
        exception caught: 0
        destructor of exception called
        Second exception
        constructor of exception called
        copy constructor of exception called
        exception caught: 0
        destructor of exception called
        destructor of exception called
        Third exception
        constructor of exception called
        copy constructor of exception called
        destructor of exception called
        exception caught: 1
        destructor of exception called
        Fourth exception
        constructor of exception called
        copy constructor of exception called
        destructor of exception called
        copy constructor of exception called
        exception caught: 1
        destructor of exception called
        destructor of exception called
        
      
ACE_OS
      namespace functions instead of bare OS system calls.
ACE_OS namespace are ones that
        have direct equivalents on some OS platform.  Functions that
        are extensions should go in the
        ACE namespace.
ACE_SYNCH_MUTEX macro,
      instead of using one of the specific mutexes, such as
      ACE_Thread_Mutex.  This provides
      portability between threaded and non-threaded platforms.
ACE_Singleton,
      ACE_TSS_Singleton, or as an
      ACE_Cleanup object.  See the
      ACE
      Singleton.h,
      Object_Manager.h, and
      Managed_Object.h
      header files for more information.
      Static instances of built-in types, such as
      int or any pointer type, are fine.
Construction of static instance of a user-defined type should never spawn threads. Because order of construction of statics across files is not defined by the language, it is usually assumed that only one thread exists during static construction. This allows statics suchs as locks to be safely created. We do not want to violate this assumption.
      ACE_NEW_RETURN (this->name_space_, LOCAL_NAME_SPACE, -1);
      if (ACE_LOG_MSG->op_status () != 0)
      ....
      
      This snip of code is from
      ACE_Naming_Context.
      All failed constructors in ACE (should) call ACE_ERROR.  This sets
      the thread-specific op_status, which can be checked
      by the caller.  This mechanism allows the caller to check for a failed
      constructor without the requiring the constructor to throw
      exceptions.
open() methods on classes that
      perform initializations that can fail.  This is because open()
      returns an error code that's easily checked by the caller,
      rather than relying on constructor and thread-specific status
      values. 
ACE_ASSERT.  It
      must only be used to check values; it may never be used to
      wrap a function call, or contain any other side effect.  That's
      because the statement will disappear when ACE_NDEBUG is enabled.
      For example, this code is BAD:
      
      ACE_ASSERT (this->next (retv) != 0);  // BAD CODE!
      
      Instead, the above should be coded this way:
      
      int result = this->next (retv);
      ACE_ASSERT (result != 0);
      ACE_UNUSED_ARG (result);
      
ACE_DEBUG code:
      
      ACE_DEBUG ((LM_DEBUG,
                 "handling signal: %d iterations left\n",
                 --this->iterations_));        // BAD CODE!
      
      Note that this won't work correctly if ACE_NDEBUG is
      defined, for the same reason that having side-effects in
      ACE_ASSERTs won't work either, i.e., because
      the code is removed.
      ACE_HANDLE h = open the file (filename);
      ACE_OS::unlink (filename);
      This avoids leaving the temporary file even if the program crashes.
$(RM) instead of rm or
      rm -f in Makefiles.
THR_BOUND thread creation
    flag for time-critical threads.  This ensures that the thread competes
    for resources globally on Solaris.  It is harmless on other platforms.
ChangeLogTag: Thu Jul 22 09:55:10 1999  David L. Levine
 <levine@cs.wustl.edu>
man perlstyle to view it.
  PATH:
eval '(exit $?0)' && eval 'exec perl -S $0 ${1+"$@"}'
    & eval 'exec perl -S $0 $argv:q'
    if 0;
      
#", unless the first line is "#! /bin/sh".
    With just "#", t/csh users will spawn a new shell.
    That will cause their .[t]cshrc to be
    processed, possibly clobbering a necessary part of
    their environment.
        require 5.003;
      
  . being
    in the user's path.  If the script spawns another executable
    that is supposed to be in the current directory, be sure the
    prefix its filename with ..
Last modified: Thu Jan 20 22:59:04 PST 2005
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