[Bug libstdc++/64128] Let vector take advantage of malloc_usable_size for malloc-using allocators

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64128

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |trippels at gcc dot gnu.org

--- Comment #3 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Or LD_PRELOAD a different malloc implementation like llalloc or tcmalloc.
llalloc (http://locklessinc.com/articles/allocator_tricks/) for example,
speeds up the testcase by 36% on my machine.