libstdc++: Fix noexcept-specifier for istream_iterator

Somehow I missed that the _M_value member can throw on construction.

	* include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
	Make noexcept-specifier conditional.
	* testsuite/24_iterators/istream_iterator/cons/sentinel.cc: Check
	noexcept-specifier.
This commit is contained in:
Jonathan Wakely 2020-02-24 14:22:21 +00:00
parent 32b8f5df9f
commit 8566286eae
3 changed files with 16 additions and 1 deletions

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@ -1,5 +1,10 @@
2020-02-24 Jonathan Wakely <jwakely@redhat.com>
* include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
Make noexcept-specifier conditional.
* testsuite/24_iterators/istream_iterator/cons/sentinel.cc: Check
noexcept-specifier.
* include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
Add constructor.
(operator==(istream_iterator, default_sentinel_t)): Add operator.

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@ -79,7 +79,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cplusplus > 201703L
constexpr
istream_iterator(default_sentinel_t) noexcept
istream_iterator(default_sentinel_t)
noexcept(is_nothrow_default_constructible_v<_Tp>)
: istream_iterator() { }
#endif

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@ -19,9 +19,18 @@
// <http://www.gnu.org/licenses/>.
#include <iterator>
#include <istream>
// C++20 doesn't require this to be non-throwing.
static_assert( std::is_nothrow_constructible_v<std::istream_iterator<int>,
std::default_sentinel_t> );
constexpr std::istream_iterator<int> i = std::default_sentinel;
struct X { X() noexcept(false); };
std::istream& operator<<(std::istream&, X&);
static_assert( std::is_constructible_v<std::istream_iterator<X>,
std::default_sentinel_t> );
static_assert( ! std::is_nothrow_constructible_v<std::istream_iterator<X>,
std::default_sentinel_t> );