https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83428
--- Comment #6 from Wolfgang Roehrl <wolfgang.roe...@gi-de.com> --- Hi Jonathan, I would like to draw your attention to my new comment on your answer to my bug report. Thank you, W. Roehrl (In reply to Jonathan Wakely from comment #4) > (In reply to Aliaksei Kandratsenka from comment #3) > > constructor is defined after variable in this example. I am not sure this > > real bug. > > Agreed. If we use Clang and add its require_constant_initialization > attribute to the variable definition it tells us: > > 83428.cc:20:54: error: variable does not have a constant initializer > __attribute__((require_constant_initialization)) S2 objX; > ^~~~ > 83428.cc:20:17: note: required by 'require_constant_initialization' > attribute here > __attribute__((require_constant_initialization)) S2 objX; > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 83428.cc:12:7: note: undefined constructor 'S1' cannot be used in a constant > expression > : m_tabS1() > ^ > 83428.cc:20:54: note: in call to 'S2()' > __attribute__((require_constant_initialization)) S2 objX; > ^ > 83428.cc:3:15: note: declared here > constexpr S1 (); > ^ > 1 error generated. > > > If the S1::S1() constructor is defined before the definition of objX then > Clang doesn't warn and GCC doesn't use dynamic initialization.
