On 13/01/16 09:53 -0700, Sandra Loosemore wrote:
On 01/13/2016 06:28 AM, Jonathan Wakely wrote:
This patch corrects the manual w.r.t the default -std mode for C++,
which changed from -std=gnu++98 to -std=gnu++14 in GCC 6. (I was
slightly surprised to find that -ansi didn't change to mean -std=c++14
at the same time, but now I think that makes sense.)
I added a cross-reference from the C++ options section to the C
options section, so people looking for documentation of -std for C++
know where to look.
I also documented C++14 and the Concepts TS in standards.texi and
removed the description of C++11 as experimental (I left C++14
described as experimental, as that's still what it says at
https://gcc.gnu.org/projects/cxx1y.html).
Rather then repeating the "to obtain all the diagnostics required by
the standard" text about -pedantic/-pedantic-errors I left it only on
the first paragraph and then added a new paragraph about it later. I
also clarified that the extensions enabled by -std=gnu++XX are
different to the ones enabled without -pedantic, taking the wording
from the previous @section about C Standards.
OK for trunk?
Thanks for doing this. I have a one big question not addressed by
your patch, and few nit-picky tech-writerish comments.
The big question is: the existing text in standards.texi says that
"GCC implements the majority of C++98 (@code{export} is a notable
exception) and most of the changes in C++03." Is it still the case
that there are unimplemented language features from these older
versions of the standard? If so, is there a detailed list anywhere of
what features are not supported, as there is for the C++11 feature
status?
The 'export' feature is definitely still not implemented, and never
will be.
The only other missing C++03 feature I can think of is
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=2316
Jason?
For the nit-picking:
@@ -2128,6 +2128,9 @@ In this example, only @option{-fstrict-enums} is an
option meant
only for C++ programs; you can use the other options with any
language supported by GCC@.
+@xref{C Dialect Options,,Options Controlling C Dialect} for the description
Texinfo style is to put a comma (or other punctuation) after "@xref{}".
OK. I originally had "For the description of -std @xref{...}" but the
"See" that @xref inserts is capitalized, so I moved it to the start of
the sentence.
How about:
Some options for compiling C programs, such as @option{-std}, are also
relevant for C++ programs.
@xref{C Dialect Options,,Options Controlling C Dialect}.
?
+of @option{-std} and other options which are also relevant for C++ programs.
s/which/that/
+
Here is a list of options that are @emph{only} for compiling C++ programs:
@table @gcctabopt
@@ -188,25 +188,48 @@ warnings).
A revised ISO C++ standard was published in 2011 as ISO/IEC
14882:2011, and is referred to as C++11; before its publication it was
commonly referred to as C++0x. C++11 contains several
-changes to the C++ language, most of which have been implemented in an
-experimental C++11 mode in GCC@. For information
-regarding the C++11 features available in the experimental C++11 mode,
-see @uref{http://gcc.gnu.org/projects/@/cxx0x.html}. To select this
-standard in GCC, use the option @option{-std=c++11}; to obtain all the
-diagnostics required by the standard, you should also specify
-@option{-pedantic} (or @option{-pedantic-errors} if you want them to
-be errors rather than warnings).
+changes to the C++ language, all of which have been implemented in GCC@.
+For information regarding the C++11 features available in C++11 mode,
You could make that a lot less verbose by just saying "For details,".
+see @uref{https://gcc.gnu.org/projects/@/cxx0x.html}. To select this
+standard in GCC, use the option @option{-std=c++11}.
+
+Another revised ISO C++ standard was published in 2014 as ISO/IEC
+14882:2014, and is referred to as C++14; before its publication it was
+sometimes referred to as C++1y. C++14 contains several further
+changes to the C++ language, all of which have been implemented in GCC@.
+For information
+regarding the C++14 features available in the experimental C++14 mode,
Ditto here.
Good idea. It was overly verbose when it appeared once, even more so
now I've duplicated that text.
+see @uref{https://gcc.gnu.org/projects/@/cxx1y.html}. To select this
+standard in GCC, use the option @option{-std=c++14}.
+
+GCC also supports the C++ Concepts Technical Specification,
+ISO/IEC TS 19217:2015, which allows constraints to be defined for templates,
+allowing template arguments to be checked and for templates to be
+overloaded or specialized based on the constraints. Support for C++ Concepts
+is included in an experimental C++1z mode that corresponds to the next
+revision of the ISO C++ standard, expected to be published in 2017. To enable
+C++1z support in GCC, use the option @option{-std=c++17} or
+@option{-std=c++1z}.
More information about the C++ standards is available on the ISO C++
committee's web site at @uref{http://www.open-std.org/@/jtc1/@/sc22/@/wg21/}.
-By default, GCC provides some extensions to the C++ language; @xref{C++
+To obtain all the diagnostics required by any of the standard versions
+described above you should specify @option{-pedantic}
+or @option{-pedantic-errors}, otherwise GCC will allow some non-ISO C++
+features as extensions. @xref{Warning Options}.
+
+By default, GCC also provides some additional extensions to the C++ language
+that on rare occasions conflict with the C++ standard. @xref{C++
Dialect Options,Options Controlling C++ Dialect}. Use of the
-@option{-std} option listed above will disable these extensions. You
-may also select an extended version of the C++ language explicitly with
-@option{-std=gnu++98} (for C++98 with GNU extensions) or
-@option{-std=gnu++11} (for C++11 with GNU extensions). The default, if
-no C++ language dialect options are given, is @option{-std=gnu++98}.
+@option{-std} options listed above will disable these extensions where they
s/will disable/disables/
(assuming this is an already-implemented feature and not something
that will be added at some future date....)
Agreed. That was copied from existing text in the previous section,
should I make the same change there?
