[Bug c++/49813] [C++0x] sinh vs asinh vs constexpr

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49813

--- Comment #42 from Jason Merrill <jason at gcc dot gnu.org> 2011-07-26 00:10:20 UTC ---
(In reply to comment #34)
> (we *do* have PRs about constexpr vs diagnostics)

Notably 45923, which I have just closed as fixed by my June 29 patch.

The comment 8 testcase results in errors like

wa.C:16:64: error: call to non-constexpr function ‘float std::nextafter(float,
float)’
wa.C:16:64: error: field initializer is not constant
...

which seems plenty clear to me: the initializer is not constant because of the
call to a non-constexpr function.

The isinf issue has to do with the (...) signature;
morally_constexpr_builtin_function_p rejects varargs.  Seems like we should add
BUILT_IN_ISINF and its variants to builtin_valid_in_constant_expr_p.