OS/2 info added

[wxWidgets.git] / docs / html / standard.htm

diff --git a/docs/html/standard.htm b/docs/html/standard.htm
index fc3c4db0a1015f2a2c199ed8a5e7377094b7ed23..9bd3acac5349c457692a270cd613c98c9591c72b 100644 (file)
--- a/docs/html/standard.htm
+++ b/docs/html/standard.htm
@@ -50,7 +50,13 @@ C++ portability guide</A> by David Williams.
     <LI><A HREF="#no_stl">Don't use STL</A></LI>
     <LI><A HREF="#no_fordecl">Don't declare variables inside <TT>for()</TT></A></LI>
     <LI><A HREF="#no_nestedclasses">Don't use nested classes</A></LI>
+  </OL>
+  <BR>
+  <LI>Other compiler limitations</LI>
+  <OL>
     <LI><A HREF="#no_ternarywithobjects">Use ternary operator ?: carefully</A></LI>
+    <LI><A HREF="#no_autoaggregate">Don't use initializers with automatic arrays</A></LI>
+    <LI><A HREF="#no_dtorswithoutctor">Always have at least one constructor in a class with destructor</A></LI>
   </OL>
   <BR>
   <LI>General recommendations</LI>
@@ -332,7 +338,17 @@ you can try the following:
 <P>A nice side effect is that you don't need to recompile all the files
 including the header if you change the PrivateLibClass declaration (it's
 an example of a more general interface/implementation separation idea).
+</OL>
+
+  <BR>
+  <LI>Other compiler limitations</B></LI><P>
+This section lists the less obvious limitations of the current C++ compilers
+which are less restrictive than the ones mentioned in the previous section but
+are may be even more dangerous as a program which compiles perfectly well on
+some platform and seems to use only standard C++ featurs may still fail to
+compile on another platform and/or with another compiler.
 
+<OL>
   <P><LI><A NAME="no_ternarywithobjects"></A><B>Use ternary operator ?: carefully</B></LI><P>
   The ternary operator <TT>?:</TT> shouldn't be used with objects (i.e. if any
 of its operands are objects) because some compilers (notable Borland C++) fail
@@ -351,6 +367,24 @@ to compile such code.
     else
         s = s2;
 </PRE>
+
+   <P><LI><A NAME="no_autoaggregate"></A><B>Don't use initializers with automatic arrays</B></LI><P>
+The initializers for automatic array variables are not supported by some older
+compilers. For example, the following line
+<PRE>
+    int daysInMonth[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+</PRE>
+will fail to compile with HP-UX C++ compiler.
+<P><U>Workaround</U>: either make the array static or initialize each item
+separately: in the (stupid) example above, the array should be definitely
+declared as <TT>static const</TT> (assuming that the leap years are dealt with
+elsewhere somehow...) which is ok. When an array is really not const, you
+should initialize each element separately.
+
+   <P><LI><A NAME="no_dtorswithoutctor"></A><B>Always have at least one constructor in a class with destructor</B></LI><P>
+It is a good rule to follow in general, but some compilers (HP-UX) enforce it.
+So even if you are sure that the default constructor for your class is ok but
+it has a destructor, remember to add an empty default constructor to it.
 </OL>
 
   <BR>
@@ -595,7 +629,7 @@ about terminating the last line.
 The linker on VMS is case-insensitive. Therefore all external variables and
 functions which differ only in case are not recognized by the linker as
 different, so all externals should differ in more than the case only:
-i.e. <TT>GetId</TT> is the same as <TT><GetID</TT>. 
+i.e. <TT>GetId</TT> is the same as <TT>GetID</TT>. 
 
   </OL>
 
@@ -730,8 +764,8 @@ the right header for given platform. Any new headers should conform to this
 setup as well to allow including <TT>&lt;wx/foo.h&gt;</TT> on any platform.<P>
 
 Note that wxWindows implementation files should use quotes when including wxWindows
-headers, not angled brackets. Applications should use angled brackets. There
-is a reason for it (can anyone remember what this is?).
+headers, not angled brackets. Applications should use angled brackets. This
+ensures that the dependencies are correctly handled by the compiler.
 
     <P><LI><A NAME="include_guards"></LI><B>Include guards</B><P>
 To minimize the compile time C++ programmers often use so called include
@@ -835,12 +869,6 @@ WXDLLEXPORT_DATA(extern wxApp*) wxTheApp;
 The reason for the strange syntax for data is that some compilers use different
 keyword ordering for exporting data.
 
-<P>There also several other places where you should take care of shared
-library case: all IMPLEMENT_xxx macros which are usually used in the
-corresponding .cpp files must be taken inside
-"<TT>&#35;if !USE_SHARED_LIBRARY</TT>" and in the <TT>&#35;if USE_SHARED_LIBRARY</TT>
-case you should put them inside <TT>common/cmndata.cpp</TT> file.
-
     <P><LI><A NAME="set_get"></LI><B>Use Set/Get prefixes for accessors</B><P>
 There is a convention in wxWindows to prefix the accessors (i.e. any simple, in
 general, inline function which does nothing else except changing or returning