https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63220
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
First of all you should mark the functions 'inline' as well. Then the issue
is that 'eq' is called indirectly which isn't allowed for always_inline
functions:
t.C:81:66: error: inlining failed in call to always_inline 'static constexpr
bool std::__1::char_traits<char>::eq(std::__1::char_traits<char>::char_type,
std::__1::char_traits<char>::char_type)': indirect function call with a yet
undetermined callee
__attribute__ (( __always_inline__)) static constexpr bool eq(char_type
__c1, char_type __c2) {
^
t.C:75:37: error: called from here
if (!__pred(*__m1, *__m2)) { }
^
which means this is a missed-optimization only. The error is your fault.
Note that getting the error is unreliable so -O0 simply doesn't discover the
failed inlining.
