[Bug c++/116476] [14 Regression] error: binding reference of type 'int&&' to 'const int' discards qualifiers for std::vector> f{2}; (OK under Clang and GCC<=13)

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116476

--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-14 branch has been updated by Marek Polacek
<mpola...@gcc.gnu.org>:

https://gcc.gnu.org/g:0784e8934e96187e17c1b02dce1e0ed35d2229dd

commit r14-10799-g0784e8934e96187e17c1b02dce1e0ed35d2229dd
Author: Marek Polacek <pola...@redhat.com>
Date:   Wed Aug 28 15:45:49 2024 -0400

    c++: wrong error due to std::initializer_list opt [PR116476]

    Here maybe_init_list_as_array gets elttype=field, init={NON_LVALUE_EXPR
<2>}
    and it tries to convert the init's element type (int) to field
    using implicit_conversion, which works, so overall maybe_init_list_as_array
    is successful.

    But it constifies init_elttype so we end up with "const int".  Later,
    when we actually perform the conversion and invoke field::field(T&&),
    we end up with this error:

      error: binding reference of type 'int&&' to 'const int' discards
qualifiers

    So I think maybe_init_list_as_array should try to perform the conversion,
    like it does below with fc.

            PR c++/116476

    gcc/cp/ChangeLog:

            * call.cc (maybe_init_list_as_array): Try convert_like and see if
it
            worked.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/initlist-opt2.C: New test.

    Reviewed-by: Jason Merrill <ja...@redhat.com>
    (cherry picked from commit 9f79c7ddff5f1b004803931406ad17eaba095fff)