profile mode fix

Jonathan Wakely
Sun Jan 26 10:38:00 GMT 2014

On 26 January 2014 09:43, François Dumont wrote:
> Hi
>     This is a patch to fix PR 55033 in profile mode. Like in debug mode it
> was missing noexcept qualifier on move constructor.

But don't those functions allocate memory? So they can throw.

I agree we want the move constructor to be noexcept anyway, and maybe
the default constructor, but why would we want to lie about the copy

I have this patch in my tree that I'm trying to decide whether it
should be committed, but if we make the change we should have a
comment like this:

--- a/libstdc++-v3/include/profile/unordered_base.h
+++ b/libstdc++-v3/include/profile/unordered_base.h
@@ -160,9 +160,14 @@ namespace __profile
         __profcxx_hashtable_construct(&__uc, __uc.bucket_count());
       _Unordered_profile(const _Unordered_profile&)
        : _Unordered_profile() { }
-      _Unordered_profile(_Unordered_profile&&)
+      // This might actually throw, but for consistency with normal mode
+      // unordered containers we want the noexcept specification, and will
+      // std::terminate() if an exception is thrown.
+      _Unordered_profile(_Unordered_profile&&) noexcept
        : _Unordered_profile() { }

       ~_Unordered_profile() noexcept

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