4 ms·

I bookmarked those posts a while ago in the hopes that I'll get a chance to rewrite VC's unordered_map in the future. We've taken the first step towards doing s

I bookmarked those posts a while ago in the hopes that I'll get a chance to rewrite VC's unordered_map in the future. We've taken the first step towards doing so by deprecating the non-Standard hash_map (which shares its guts with the Standard unordered_map) in 2015, so I can remove it outright at the beginning of the next development cycle. Then the unordered family can be changed without fear of breaking the hash family.

nly 11y ago
Thanks for what you do STL (For those that don't know, Stephan maintains Microsofts C++ standard library). Even though I don't develop against MSVC at all, improving the state of C++ at Microsoft makes life easier for all of us in terms of portability and bringing nice new things in to common use. Thank you also for maintaining your GCC distro for Windows[0] and the the many great presentations you have given at CppCon, Channel 9, Going Native etc. [0] http://nuwen.net/mingw.html http://nuwen.net/mingw.html
- StephanTLavavej 11y ago
  You're welcome! And even if you don't use VC's STL, hopefully make_unique and the other things I've designed will be helpful.
  - nly 11y ago
    And for making this possible vector<int> v = {1,2,3,4,5}; cout << accumulate(begin(v), end(v), 1, multiplies<>());
  - jaytaylor 11y ago
    I'm curious.. Is it possible to use VIsual C++'s STL inside of Linux?
    - StephanTLavavej 11y ago
      Nope, our sources assume they're running on Windows.
gsg 11y ago
That's an admirable sentiment, but aren't your hands tied by the promises made by the standard? In particular the addresses of elements are guaranteed to be stable, which would seem to prevent an implementor from relocating them to achieve more cache-friendly layout. (Of course, you would want to do as well as possible within the given bounds.)
- StephanTLavavej 11y ago
  Yeah, unordered_meow is always going to be a pretty crummy hash table. But our implementation could be significantly improved while still obeying the Standard.
  - gsg 11y ago
    Fair enough! Good luck with your rewrite.
joaquintides 11y ago
You might also consult the entries given below, which take into account some late improvements in Boost.MultiIndex not present at the beginning of the series: http://bannalia.blogspot.com/2014/01/a-better-hash-table.html http://bannalia.blogspot.com/2014/01/a-better-hash-table.htm... http://bannalia.blogspot.com/2014/01/a-better-hash-table-gcc.html http://bannalia.blogspot.com/2014/01/a-better-hash-table-gcc... http://bannalia.blogspot.com/2014/01/a-better-hash-table-clang.html http://bannalia.blogspot.com/2014/01/a-better-hash-table-cla...

nly 11y ago

Thanks for what you do STL (For those that don't know, Stephan maintains Microsofts C++ standard library). Even though I don't develop against MSVC at all, improving the state of C++ at Microsoft makes life easier for all of us in terms of portability and bringing nice new things in to common use. Thank you also for maintaining your GCC distro for Windows[0] and the the many great presentations you have given at CppCon, Channel 9, Going Native etc. [0] http://nuwen.net/mingw.html http://nuwen.net/mingw.html

StephanTLavavej 11y ago
You're welcome! And even if you don't use VC's STL, hopefully make_unique and the other things I've designed will be helpful.
- nly 11y ago
  And for making this possible vector<int> v = {1,2,3,4,5}; cout << accumulate(begin(v), end(v), 1, multiplies<>());
- jaytaylor 11y ago
  I'm curious.. Is it possible to use VIsual C++'s STL inside of Linux?
  - StephanTLavavej 11y ago
    Nope, our sources assume they're running on Windows.

gsg 11y ago

That's an admirable sentiment, but aren't your hands tied by the promises made by the standard? In particular the addresses of elements are guaranteed to be stable, which would seem to prevent an implementor from relocating them to achieve more cache-friendly layout. (Of course, you would want to do as well as possible within the given bounds.)

StephanTLavavej 11y ago
Yeah, unordered_meow is always going to be a pretty crummy hash table. But our implementation could be significantly improved while still obeying the Standard.
- gsg 11y ago
  Fair enough! Good luck with your rewrite.

joaquintides 11y ago

You might also consult the entries given below, which take into account some late improvements in Boost.MultiIndex not present at the beginning of the series: http://bannalia.blogspot.com/2014/01/a-better-hash-table.html http://bannalia.blogspot.com/2014/01/a-better-hash-table.htm... http://bannalia.blogspot.com/2014/01/a-better-hash-table-gcc.html http://bannalia.blogspot.com/2014/01/a-better-hash-table-gcc... http://bannalia.blogspot.com/2014/01/a-better-hash-table-clang.html http://bannalia.blogspot.com/2014/01/a-better-hash-table-cla...