| Message ID | 20160211142000.GB3163@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 11/02/16 15:20 +0100, Marek Polacek wrote: >Does this look ok? Looks OK, although how about stressing that it was only allowed as an extension previously, e.g. ... >Index: porting_to.html >=================================================================== >RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-6/porting_to.html,v >retrieving revision 1.9 >diff -u -r1.9 porting_to.html >--- porting_to.html 10 Feb 2016 17:21:54 -0000 1.9 >+++ porting_to.html 11 Feb 2016 14:18:59 -0000 >@@ -269,6 +269,25 @@ > to port the code to use C++11's <code>std::unique_ptr</code> instead. > </p> > >+<h3>'constexpr' needed for in-class initialization of static data member</h3> >+ In C++98 in-class initialization of static data members is only allowed for integral types, but as an extension G++ also allowed it for floating point types: >+ >+<pre><code> >+struct X { >+ const static double i = 10; >+}; >+</pre></code> The C++11 standard supports that in-class initialization using <code>constexpr</code> instead, so the GNU extension is no longer supported for C++11 or later. Programs relying on the extension will be rejected with an error. The fix is to use <code>constexpr</code> instead of <code>const</code>.
Index: porting_to.html =================================================================== RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-6/porting_to.html,v retrieving revision 1.9 diff -u -r1.9 porting_to.html --- porting_to.html 10 Feb 2016 17:21:54 -0000 1.9 +++ porting_to.html 11 Feb 2016 14:18:59 -0000 @@ -269,6 +269,25 @@ to port the code to use C++11's <code>std::unique_ptr</code> instead. </p> +<h3>'constexpr' needed for in-class initialization of static data member</h3> + +<p> +Since C++11, the <code>constexpr</code> keyword is needed when initializing +a non-integral static data member in a class. Thus the following program is +accepted in C++03 (albeit with a <tt>-Wpedantic</tt> warning): +</p> + +<pre><code> +struct X { + const static double i = 10; +}; +</pre></code> + +<p> +While in C++11, the program above is rejected with an error. The fix is to +use <code>constexpr</code> instead of <code>const</code>. +</p> + <h2>-Wmisleading-indentation</h2> <p> A new warning <code>-Wmisleading-indentation</code> was added