Hi, I was just rewriting some old code with hard coded indices for array access and though that compile-time checked access to array elements would be a nice thing. Maybe there are smart compilers out there that emit warnings or errors for a hard coded out-of-bounds access, but my compiler does not. So, code like compiles without warnings or erros. Now, adding the following functions to array would make it possible to write which results in the expected error messages. Tobias -- View this message in context: http://boost.2283326.n4.nabble.com/array-compile-time-checked-access-tp46381... Sent from the Boost - Dev mailing list archive at Nabble.com.
2012/11/5 Tobias Loew <Tobias.Loew@steag.com>
Hi,
I was just rewriting some old code with hard coded indices for array access and though that compile-time checked access to array elements would be a nice thing. Maybe there are smart compilers out there that emit warnings or errors for a hard coded out-of-bounds access, but my compiler does not.
So, code like
compiles without warnings or erros. Now, adding the following functions to array
would make it possible to write
which results in the expected error messages.
I see only the blanks, any code there?
I used the "raw"-tag to quote the code. Here is it again without the tags: ... So, code like boost::array<int,2> test; test[2] = 1; test[-1] = 1; compiles without warnings or erros. Now, adding the following functions to array template<size_type i> reference at() { BOOST_STATIC_ASSERT( (i < N) ); return elems[i]; } template<size_type i> const_reference at() const { BOOST_STATIC_ASSERT( (i < N) ); return elems[i]; } would make it possible to write boost::array<int,2> test; test.at<2> = 1; test.at<-1> = 1; which results in the expected error messages. -- View this message in context: http://boost.2283326.n4.nabble.com/array-compile-time-checked-access-tp46381... Sent from the Boost - Dev mailing list archive at Nabble.com.
On Mon, Nov 5, 2012 at 6:02 AM, Tobias Loew <Tobias.Loew@steag.com> wrote:
I used the "raw"-tag to quote the code. Here is it again without the tags:
... So, code like
boost::array<int,2> test; test[2] = 1; test[-1] = 1;
compiles without warnings or erros. Now, adding the following functions to array
template<size_type i> reference at() { BOOST_STATIC_ASSERT( (i < N) ); return elems[i]; }
template<size_type i> const_reference at() const { BOOST_STATIC_ASSERT( (i < N) ); return elems[i]; }
would make it possible to write
boost::array<int,2> test; test.at<2> = 1; test.at<-1> = 1;
which results in the expected error messages.
You can try to use boost::fusion::at_c<N>(test), but not sure if it actually has a static assertion. See http://www.boost.org/doc/libs/1_51_0/libs/fusion/doc/html/fusion/sequence/in... http://www.boost.org/doc/libs/1_51_0/libs/fusion/doc/html/fusion/adapted/boo... - Jeff
Jeffrey Lee Hellrung, Jr.-2 wrote
On Mon, Nov 5, 2012 at 6:02 AM, Tobias Loew <
Tobias.Loew@
> wrote:
I used the "raw"-tag to quote the code. Here is it again without the tags:
... So, code like
boost::array<int,2> test; test[2] = 1; test[-1] = 1;
compiles without warnings or erros. Now, adding the following functions to array
template <size_type i> reference at() { BOOST_STATIC_ASSERT( (i < N) ); return elems[i]; }
template <size_type i> const_reference at() const { BOOST_STATIC_ASSERT( (i < N) ); return elems[i]; }
would make it possible to write
boost::array<int,2> test; test.at<2> = 1; test.at<-1> = 1;
which results in the expected error messages.
You can try to use boost::fusion::at_c <N> (test), but not sure if it actually has a static assertion. See
http://www.boost.org/doc/libs/1_51_0/libs/fusion/doc/html/fusion/sequence/in... http://www.boost.org/doc/libs/1_51_0/libs/fusion/doc/html/fusion/adapted/boo...
- Jeff
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I tried it, but it doesn't static assert. Shouldn't it ? -- View this message in context: http://boost.2283326.n4.nabble.com/array-compile-time-checked-access-tp46381... Sent from the Boost - Dev mailing list archive at Nabble.com.
Mathias Gaunard-2 wrote
On 05/11/12 15:57, Tobias Loew wrote:
I tried it, but it doesn't static assert. Shouldn't it ?
That's trivial to add. You can add a ticket about it you want it.
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Good idea. I've added a ticket #7651 <https://svn.boost.org/trac/boost/ticket/7651> -- View this message in context: http://boost.2283326.n4.nabble.com/array-compile-time-checked-access-tp46381... Sent from the Boost - Dev mailing list archive at Nabble.com.
Hi, I cannot see any code but only newlines in your post, so I will not respond to the example. The sort of analysis you are looking for is done by static analysis tools (as far as possible, there are limitations). A classic one would be lint, but I don't know if they catch such errors. The documentation says that they do value tracking and some form of abstract interpretation. You should be able to find a lot of (commercial) tools with google if you search for static analysis c++. Klocwork and QA Systems are well-known vendors I know about. The MS compiler also has some static analysis facilities and there exists a free static analyzer based on clang: http://clang-analyzer.llvm.org/. Best regards, Jens -----Ursprüngliche Nachricht----- Von: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] Im Auftrag von Tobias Loew Gesendet: Montag, 5. November 2012 09:51 An: boost@lists.boost.org Betreff: [boost] [array] compile-time checked access Hi, I was just rewriting some old code with hard coded indices for array access and though that compile-time checked access to array elements would be a nice thing. Maybe there are smart compilers out there that emit warnings or errors for a hard coded out-of-bounds access, but my compiler does not. So, code like compiles without warnings or erros. Now, adding the following functions to array would make it possible to write which results in the expected error messages. Tobias -- View this message in context: http://boost.2283326.n4.nabble.com/array-compile-time-checked-access-tp46381... Sent from the Boost - Dev mailing list archive at Nabble.com. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
That's right, there are a lot of tools to do static analysis. But why use a tool if you can do it within the language? Jens Auer-5 wrote
The MS compiler also has some static analysis facilities and there exists a free static analyzer based on clang: http://clang-analyzer.llvm.org/.
I'm using MSVC 9 and #include <boost/array.hpp> void foo() { boost::array<int,2> test; test[2] = 1; } is compiled without any warning even though /W4 is enabled. Tobias -- View this message in context: http://boost.2283326.n4.nabble.com/array-compile-time-checked-access-tp46381... Sent from the Boost - Dev mailing list archive at Nabble.com.
participants (5)
-
Jeffrey Lee Hellrung, Jr. -
Jens Auer -
Mathias Gaunard -
Tobias Loew -
TONGARI