https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110139
--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:32f2b0f32816af816605dbe8060fb903cf7d5603 commit r13-7418-g32f2b0f32816af816605dbe8060fb903cf7d5603 Author: Jonathan Wakely <jwak...@redhat.com> Date: Tue Jun 6 11:38:42 2023 +0100 libstdc++: Fix ambiguous expression in std::array<T, 0>::front() [PR110139] For 32-bit targets using -pedantic (or using Clang) makes the expression _M_elems[0] ambiguous. The overloaded operator[] that we want to call has a size_t parameter, but 0 is type ptrdiff_t for many ILP32 targets, so using the implicit conversion from _M_elems to T* and then subscripting that is also viable. Change the 0 to (size_type)0 and also make the conversion to T* explicit, so that's it's not viable here. The latter change requires a static_cast in data() where we really do want to convert _M_elems to a pointer. libstdc++-v3/ChangeLog: PR libstdc++/110139 * include/std/array (__array_traits<T, 0>::operator T*()): Make conversion operator explicit. (array::front): Use size_type as subscript operand. (array::data): Use static_cast to make conversion explicit. * testsuite/23_containers/array/element_access/110139.cc: New test. (cherry picked from commit 56001fad4ecc32396beead6644906e3846244b67)
