https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116473
Bug ID: 116473
Summary: std::ranges::to vs constexpr
Product: gcc
Version: 14.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: terra at gnome dot org
Target Milestone: ---
Created attachment 58987
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58987&action=edit
Preprocessed source code
I *think* the following ought to work with the "constexpr". It works fine
without and in that case generates code with 3 run-time calls to operator new
and operator delete each.
# cat ttt-ranges-to.C
#include <ranges>
#include <vector>
int
oink(void)
{
constexpr auto v = std::views::iota(1,5) |
std::ranges::to<std::vector<int>>();
return v.front();
}
# /usr/local/products/gcc/14.1.0/bin/g++ -std=c++23 -c ttt-ranges-to.C
In file included from
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/string:43,
from
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/bits/locale_classes.h:40,
from
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/bits/ios_base.h:41,
from
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/streambuf:43,
from
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/bits/streambuf_iterator.h:35,
from
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/iterator:66,
from
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/ranges:43,
from ttt-ranges-to.C:1:
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/bits/allocator.h: In function
‘int oink()’:
/usr/local/products/gcc/14.1.0/include/c++/14.1.0/bits/allocator.h:193:52:
error: ‘std::ranges::views::__adaptor::operator|(_Range&&, _Self&&) [with _Self
= _Partial<std::ranges::__detail::_To<std::vector<int> > >; _Range =
std::ranges::iota_view<int, int>](std::ranges::to<std::vector<int> >())’ is not
a constant expression because it refers to a result of ‘operator new’
193 | return static_cast<_Tp*>(::operator new(__n));
| ~~~~~~~~~~~~~~^~~~~
