{"id":1318,"date":"2015-12-07T23:33:38","date_gmt":"2015-12-08T07:33:38","guid":{"rendered":"http:\/\/www.elbeno.com\/blog\/?p=1318"},"modified":"2015-12-07T23:33:38","modified_gmt":"2015-12-08T07:33:38","slug":"the-c-random-lame-list","status":"publish","type":"post","link":"https:\/\/www.elbeno.com\/blog\/?p=1318","title":{"rendered":"The C++ <random><\/code> Lame List"},"content":{"rendered":"

Network programmers of a certain age may remember the Windows Sockets Lame List<\/a>.<\/p>\n

I previously wrote a short “don’t-do-that-do-this” guide for modern C++ randomness<\/a>, and I was recently reading another Reddit exchange featuring STL<\/a>, author of many parts of Microsoft’s STL implementation, when it struck me that use of C++ <random><\/code> needs its own lame list to discourage using the old and busted C parts and encourage the using the new C++ hotness. So here, in no particular order, and with apologies to Keith Moore (wherever he may be) is an incomplete lame list for use of <random><\/code>.<\/p>\n

    \n
  1. Calling rand()<\/code> or srand()<\/code>. Lame.<\/strong><\/li>\n
  2. Using time(NULL)<\/code> to seed an RNG. Inexcusably lame.<\/strong><\/li>\n
  3. Claiming, “But rand()<\/code> is good enough for simple uses!” Dog lame.<\/strong><\/li>\n
  4. Using random_shuffle()<\/code> to permute a container. Mired in a sweaty mass of lameness.<\/strong><\/li>\n
  5. Using default_random_engine<\/code>. Nauseatingly lame.<\/strong><\/li>\n
  6. Using %<\/code> to get a random value in a range. Lame. Lame. Lame. Lame. Lame.<\/strong><\/li>\n
  7. Not using random_device<\/code> to seed an RNG. Violently lame<\/strong>.<\/li>\n
  8. Assuming that random_device<\/code> is going to do the right thing on your platform. Uncontrollably lame<\/strong>.<\/li>\n
  9. Failing to handle a possible exception from the construction or use of random_device<\/code>. Totally lame.<\/strong><\/li>\n
  10. Using anything in the standard but mt19937<\/code> or mt19937_64<\/code> as a generator. Intensely lame.<\/strong><\/li>\n
  11. Putting mt19937<\/code> on the stack. In all my years of observing lameness, I have seldom seen something this lame.<\/strong><\/li>\n
  12. Seeding mt19937<\/code> with only one 32-bit word rather than its full state_size<\/code>. Pushing the lameness envelope.<\/strong><\/li>\n
  13. Forgetting that uniform_int_distribution<\/code> works on a closed interval. Thrashing in a sea of lameness.<\/strong><\/li>\n
  14. Passing random_device<\/code> or a generator to generate_n()<\/code> by value, forgetting to wrap it with ref()<\/code>. Glaringly lame.<\/strong><\/li>\n
  15. Failing to use seed_seq<\/code> to initialize a generator’s state properly. Indescribably lame.<\/strong><\/li>\n
  16. Not considering thread safety when using a generator. Floundering in an endless desert of lameness.<\/strong><\/li>\n
  17. Using a global generator without making it thread_local<\/code>. Suffocating in self lameness.<\/strong><\/li>\n
  18. Using RAND_MAX<\/code> instead of mt19937::max()<\/code>. Perilously teetering on the edge of a vast chasm of lameness.<\/strong><\/li>\n<\/ol>\n

    This list will undoubtedly grow as I continue to write lame code…<\/p>\n","protected":false},"excerpt":{"rendered":"

    Network programmers of a certain age may remember the Windows Sockets Lame List. I previously wrote a short “don’t-do-that-do-this” guide for modern C++ randomness, and I was recently reading another Reddit exchange featuring STL, author of many parts of Microsoft’s STL implementation, when it struck me that use of C++…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[],"class_list":["post-1318","post","type-post","status-publish","format-standard","hentry","category-cpp"],"_links":{"self":[{"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1318","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1318"}],"version-history":[{"count":6,"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1318\/revisions"}],"predecessor-version":[{"id":1324,"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1318\/revisions\/1324"}],"wp:attachment":[{"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1318"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1318"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.elbeno.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1318"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}