https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121132
Bug ID: 121132
Summary: `__extension__` doesn't silence -pedantic warning for
hex float in C++<17
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: roland at gnu dot org
Target Milestone: ---
`double x = (__extension__ 0x123p4);` when compiled under `-std=c++11
-pedantic` still emits `warning: use of C++17 hexadecimal floating constant`.
The purpose of `__extension__` is to prevent this sort of warning, for
newer-standard features as well as for GNU extension features. Clang properly
suppresses this warning when `__extension__` is used.
