[Bug c++/99610] New: GCC thinks member function template is a deduction guide

[gcchelp.5.adept at 0sg dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99610

            Bug ID: 99610
           Summary: GCC thinks member function template is a deduction
                    guide
           Product: gcc
           Version: 8.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gcchelp.5.adept at 0sg dot net
  Target Milestone: ---

When compiling with -std=c++17 or -std=gnu++17,
the following errors are reported for the code below:

[2] error: return type specified for deduction guide
[2] error: decl-specifier in declaration of deduction guide
[2] error: 'signed' or 'unsigned' invalid for '__dguide_Hash'
[2] error: deduction guide for 'Hash<K, V, C>' must have trailing return type
[1] note: 'template<class K, class V, class C> class Hash' declared here

The same code is accepted without errors by clang and msvc 2019.
I'm not sufficiently versed in the c++ standard to tell if this is on the
compiler or not.

Thanks!


---------------------- 

[1] template< typename K, typename V, typename C = HashContext<K> >
    class Hash 
    {
        // ...
    };


    template< typename K >
    class HashContext
    {
    public:
        template< typename X >
[2]     unsigned Hash( const X &arg ) const
            { ... }
    };