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* [Bug c++/109084] New: requires keyword can't access private static constexpr bool in templated class
@ 2023-03-09 19:33 brignon.enzo at protonmail dot com
  2023-03-09 21:12 ` [Bug c++/109084] [10/11/12/13 Regression] " pinskia at gcc dot gnu.org
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: brignon.enzo at protonmail dot com @ 2023-03-09 19:33 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109084

            Bug ID: 109084
           Summary: requires keyword can't access private static constexpr
                    bool in templated class
           Product: gcc
           Version: 12.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: brignon.enzo at protonmail dot com
  Target Milestone: ---

Created attachment 54626
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54626&action=edit
The minimal reproduction file (not preprocessed because it does not include
anything)

When using requires keyword to enable class member function using a private
static constexpr bool (eventually the value of a concept) in a templated class
gcc fails to access the given boolean variable because it is private within its
context. 
It does not fail if the boolean is public or if the class is not templated.

You can find a minimal example (not preprocessed because it needs no include)
in attachment.

Output of gcc -v:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --enable-bootstrap
--prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/
--with-build-config=bootstrap-lto --with-linker-hash-style=gnu
--with-system-zlib --enable-__cxa_atexit --enable-cet=auto
--enable-checking=release --enable-clocale=gnu --enable-default-pie
--enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object
--enable-libstdcxx-backtrace --enable-link-serialization=1
--enable-linker-build-id --enable-lto --enable-multilib --enable-plugin
--enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch
--disable-werror
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.2.1 20230201 (GCC) 

The file is complied with following options:
g++ -std=c++20 bug.cpp

Output of gcc:

bug.cpp: In function 'int main()':
bug.cpp:12:15: error: class template argument deduction failed:
   12 |     MyClass c{};
      |               ^
bug.cpp:12:15: error: no matching function for call to 'MyClass()'
bug.cpp:8:5: note: candidate: 'template<class T, class Enable>  requires 
MyClass<T>::cond MyClass()-> MyClass<T>'
    8 |     MyClass() {}
      |     ^~~~~~~
bug.cpp:8:5: note:   template argument deduction/substitution failed:
bug.cpp:8:5: note: constraints not satisfied
bug.cpp: In substitution of 'template<class T, class Enable>  requires 
MyClass<T>::cond MyClass()-> MyClass<T> [with T = int; Enable = void]':
bug.cpp:12:15:   required from here
bug.cpp:8:5:   required by the constraints of 'template<class T, class Enable> 
requires  MyClass<T>::cond MyClass()-> MyClass<T>'
bug.cpp:12:15: error: 'constexpr const bool MyClass<int>::cond' is private
within this context
   12 |     MyClass c{};
      |               ^
bug.cpp:5:27: note: declared private here
    5 |     static constexpr bool cond = true;
      |                           ^~~~
bug.cpp:3:7: note: candidate: 'template<class T> MyClass(MyClass<T>)->
MyClass<T>'
    3 | class MyClass {
      |       ^~~~~~~
bug.cpp:3:7: note:   template argument deduction/substitution failed:
bug.cpp:12:15: note:   candidate expects 1 argument, 0 provided
   12 |     MyClass c{};
      |

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/109084] [10/11/12/13 Regression] requires keyword can't access private static constexpr bool in templated class
  2023-03-09 19:33 [Bug c++/109084] New: requires keyword can't access private static constexpr bool in templated class brignon.enzo at protonmail dot com
@ 2023-03-09 21:12 ` pinskia at gcc dot gnu.org
  2023-03-09 23:07 ` ppalka at gcc dot gnu.org
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-03-09 21:12 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109084

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
      Known to work|                            |10.1.0, 10.2.0
   Last reconfirmed|                            |2023-03-09
      Known to fail|                            |10.3.0, 10.4.0, 11.3.0
   Target Milestone|---                         |10.5
           Keywords|                            |rejects-valid
            Summary|requires keyword can't      |[10/11/12/13 Regression]
                   |access private static       |requires keyword can't
                   |constexpr bool in templated |access private static
                   |class                       |constexpr bool in templated
                   |                            |class
     Ever confirmed|0                           |1

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed a regression even ...

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/109084] [10/11/12/13 Regression] requires keyword can't access private static constexpr bool in templated class
  2023-03-09 19:33 [Bug c++/109084] New: requires keyword can't access private static constexpr bool in templated class brignon.enzo at protonmail dot com
  2023-03-09 21:12 ` [Bug c++/109084] [10/11/12/13 Regression] " pinskia at gcc dot gnu.org
@ 2023-03-09 23:07 ` ppalka at gcc dot gnu.org
  2023-03-09 23:12 ` ppalka at gcc dot gnu.org
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: ppalka at gcc dot gnu.org @ 2023-03-09 23:07 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109084

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=96199,
                   |                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=105220
                 CC|                            |jason at gcc dot gnu.org,
                   |                            |ppalka at gcc dot gnu.org
           Keywords|needs-bisection             |

--- Comment #2 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Started with r11-2747-g9125cf8c33b710, which was also backported to the 10
branch.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/109084] [10/11/12/13 Regression] requires keyword can't access private static constexpr bool in templated class
  2023-03-09 19:33 [Bug c++/109084] New: requires keyword can't access private static constexpr bool in templated class brignon.enzo at protonmail dot com
  2023-03-09 21:12 ` [Bug c++/109084] [10/11/12/13 Regression] " pinskia at gcc dot gnu.org
  2023-03-09 23:07 ` ppalka at gcc dot gnu.org
@ 2023-03-09 23:12 ` ppalka at gcc dot gnu.org
  2023-03-10  8:07 ` rguenth at gcc dot gnu.org
  2023-07-07 10:45 ` [Bug c++/109084] [11/12/13/14 " rguenth at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: ppalka at gcc dot gnu.org @ 2023-03-09 23:12 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109084

--- Comment #3 from Patrick Palka <ppalka at gcc dot gnu.org> ---
template<typename T>
class MyClass {
  private:
    static constexpr bool cond = true;
  public:
    MyClass(T) requires cond;
};

MyClass c{0};


The problem seems to be that the access context during satisfaction of #1's
implicit guide [with T=int] is MyClass<T> instead of MyClass<int>, and
MyClass<int>::cond (the substituted result of maybe_dependent_member_ref) is
considered inaccessible from MyClass<T>.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/109084] [10/11/12/13 Regression] requires keyword can't access private static constexpr bool in templated class
  2023-03-09 19:33 [Bug c++/109084] New: requires keyword can't access private static constexpr bool in templated class brignon.enzo at protonmail dot com
                   ` (2 preceding siblings ...)
  2023-03-09 23:12 ` ppalka at gcc dot gnu.org
@ 2023-03-10  8:07 ` rguenth at gcc dot gnu.org
  2023-07-07 10:45 ` [Bug c++/109084] [11/12/13/14 " rguenth at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-03-10  8:07 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109084

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Bug c++/109084] [11/12/13/14 Regression] requires keyword can't access private static constexpr bool in templated class
  2023-03-09 19:33 [Bug c++/109084] New: requires keyword can't access private static constexpr bool in templated class brignon.enzo at protonmail dot com
                   ` (3 preceding siblings ...)
  2023-03-10  8:07 ` rguenth at gcc dot gnu.org
@ 2023-07-07 10:45 ` rguenth at gcc dot gnu.org
  4 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-07-07 10:45 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109084

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2023-07-07 10:45 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-03-09 19:33 [Bug c++/109084] New: requires keyword can't access private static constexpr bool in templated class brignon.enzo at protonmail dot com
2023-03-09 21:12 ` [Bug c++/109084] [10/11/12/13 Regression] " pinskia at gcc dot gnu.org
2023-03-09 23:07 ` ppalka at gcc dot gnu.org
2023-03-09 23:12 ` ppalka at gcc dot gnu.org
2023-03-10  8:07 ` rguenth at gcc dot gnu.org
2023-07-07 10:45 ` [Bug c++/109084] [11/12/13/14 " rguenth at gcc dot gnu.org

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