[Bug c++/61057] New: [C++11] operator . considered part of User Defined Literal invocation.

[Bug c++/61057] New: [C++11] operator . considered part of User Defined Literal invocation.

[isupeene at ualberta dot ca]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61057

            Bug ID: 61057
           Summary: [C++11] operator . considered part of User Defined
                    Literal invocation.
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: isupeene at ualberta dot ca

Created attachment 32730
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32730&action=edit
Contains udl_bug.cpp and udl_bug_workaround.cpp

When compiling with 'g++ -std=c++11 <filename>':

The attached file udl_bug.cpp reproduces the bug, producing the error: "error:
unable to find numeric literal operator ‘operator"" _i.m_value’".

The attached file udl_bug_workaround.cpp compiles successfully and produces the
expected output.
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id`014

--- Comment #1 from Fredrik Hallenberg <megahallon at gmail dot com> ---
Same results with gcc 4.9.0

[Bug c++/61057] [C++11] operator . considered part of User Defined Literal invocation.

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61057

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |emsr at gcc dot gnu.org

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Reduced:

class Int {
public:
    constexpr Int(long long unsigned value)
        : m_value(value)
    {}
    const long long unsigned m_value;
};

constexpr Int operator "" _i(long long unsigned i) {
    return Int(i);
}

auto x = 1_i.m_value;

I think G++ is correct, the grammar in the standard defines 1_i.m_value as a
pp-number, i.e. a single preprocessing token, which is treated as a literal, so
_i.m_value is looked up as the suffix.

Clang gives the same error.

[Bug c++/61057] [C++11] operator . considered part of User Defined Literal invocation.

[emsr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61057

emsr at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #2 from emsr at gcc dot gnu.org ---
As someone who has dabbled in Ruby I am sympathetic to the request to have this
work.  After looking at the standard language and our implementation I must
conclude that your code is invalid.  I then tried to imagine a way, for
example, if the stuff after a dot could not be a mantissa stop processing chars
at the dot so the remainder can become an invocation or access.  Unfortunately,
123. is a valid double so this idea can't work even as an extension.

FWIW, character and string user-defined literals can have invocations like
"Hello, World!!!"s.length().

Perhaps two dots could signal a termination of a literal as was tried for '_'
as digit separator.  This would require much noodling by the standards folks
though.

I'll ponder this last idea but I'll mark this as resolved invalid.

[Bug c++/61057] [C++11] operator . considered part of User Defined Literal invocation.

[emsr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61057

--- Comment #3 from emsr at gcc dot gnu.org ---
Leaving a space before the dot also works.