https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117785
--- Comment #31 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
what() is printed if derived from std::exception, constexpr, etc.
E.g.
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh9.C:108:23: in
'constexpr' expansion of 'bar(1)'
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh9.C:82:1: error:
'std::terminate' called after throwing an exception of type 'S'; 'what()':
'this is S'
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh9.C:82:1: note: uncaught
exception exited from 'noexcept' function 'constexpr int bar(int)'
or
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh9.C:123:25: error: uncaught
exception of type 'T'; 'what()': 'hello, world'
Or it prints the content of the exception object, like:
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh9.C:110:23: in
'constexpr' expansion of 'bar(3)'
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh9.C:82:1: error:
'std::terminate' called after throwing an exception 'U{1, -2, 42}'
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh9.C:82:1: note: uncaught
exception exited from 'noexcept' function 'constexpr int bar(int)'
or
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh9.C:125:25: error: uncaught
exception '42'
Or as last fallback it prints just the type
/usr/src/gcc/gcc/testsuite/g++.dg/cpp26/constexpr-eh12.C:71:49: error: uncaught
exception of type 'E*'
This was e.g. when E is a class with int * member initialized by new int, in
that case printing the value is I think not what users want to see.
