no blocking due to scheduler interruption between two operations, like placing data and increment index 16 CppCon 2024 | Erez Strauss | Lockfree, MPMC Queue https://github.com/erez-strauss/lockfree_mpmc_queueC++ 2^N ], atomic entries are 8 or 16 bytes, aligned to cachline. ● Each Entry contains: 1. Sequence/Index, 2. data-flag, 3. data-value ● Entries in the array are modified only using CAS operations (Compare typename IndexT = uint32_t, // index type: 4 or 8 bytes bool lazy_push = false, // delay write index increment bool lazy_pop = false> // delay read index increment class mpmc_queue

Library (STL) template template constexpr variant::variant(T&& t) : index{find_index} // Powered by TMP , // ... { } 5 / 58[Examples] Standard Template Library (STL) Library (STL) template template constexpr variant::variant(T&& t) : index{find_index} // Powered by TMP , // ... { } template constexpr auto get(tuple template constexpr variant::variant(T&& t) : index{find_index} // Powered by TMP , // ... { } template constexpr auto get(tuple

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synopsis as of P0009R10 1 template 2 class extents { 3 public: 4 using index_type = ptrdiff_t; 5 6 // [mdspan.extents.cons], Constructors and assignment 7 constexpr extents () multidimensional index space 21 static constexpr size_t rank () noexcept; 22 static constexpr size_t rank_dynamic () noexcept; 23 static constexpr index_type static_extent (size_t ); 24 constexpr index_type extent(size_t) extent(size_t) const noexcept; 25 26 private: 27 static constexpr size_t dynamic_index (size_t) noexcept; // exposition only 28 array <index_type , rank_dynamic ()> dynamic_extents_ {}; // exposition only 29 };

LIFO. ● Don’t shift contents when an element that is not in the ends is removed. ● Add the index and it’s pool into the free list.Free List Trivial solutions to remaining problems: ● Introduce LIFO. ● Don’t shift contents when an element that is not in the ends is removed. ● Add the index and it’s pool into the free list.Free List Trivial solutions to remaining problems: ● Introduce LIFO. ● Don’t shift contents when an element that is not in the ends is removed. ● Add the index and it’s pool into the free list.Free List Trivial solutions to remaining problems: ● Introduce

sized grid Put from those locations items into cells Store non-empty cells in a map - using array index as key Ideally to simplify math and logic - form from a big cube - centered on origin Speaker notesGRID Take memory into account - depending on world and cell size - could be many cells Speaker notesCELL INDEX FROM 3D COORDINATE struct GridDimensions { uint32_t cell_count; // Number of cells in each axis calculate cell index which contains given 3d coordinates Normalises 3d coordinates into indexes Combine indexes into one - like multi-dimensional array index Speaker notesCELL BOUNDS FROM INDEX struct GridDimensions

information in the loop index ▪ If i is an simd index (a newly introduced class) → SIMD version ▪ If i is an integral type (e.g. an integer) → scalar version → Loaded types deduced by SIMD index type, deduction deduction propagates forward to operators Vectorized loop body with overloaded operator[](simd_index): ▪ Same code for scalar and vector version ▪ No rewrite of the loop body required simd_value(z[i]) = simd_value(x[i]) minor C++ detail: operator[] not yet globally overloadable ▪ Currently no general solution, since index is the second argument ▪ Possible workaround: macro ▪ Rewrite (but no rearrangement) necessary

desired types const auto invoker = // helper lambda [&]Index>(std::index_sequence<Index...>) { /// we need to unpack the parameter types and the indices together conversions you want. return func(std::any_cast(params[Index])...); }; return invoker(std::make_index_sequence()); } ); } https://godbolt.org/z/Y74jse1WvCopyright (span.at doesn’t exist until C++26) C++20’s explicit lambda template parameters are needed to get the index pack 12 . 20Copyright Jason Turner @le�icus emptycrate.com/idocpp The add Function We assume contained

an allocated buffer or container void foo(){ int index, value; cin >> index >> value; vector vec = { 0, 1, /* ... */ }; vec[index] = value; }Vulnerability - Injection "An injection flaw Potential out of bounds write void foo(){ std::vector vec = get_vec(); size_t index = get_index(); vec[index] = 42; }Static vs Runtime – Bounds Check Bounds check at runtime with vector::at. be statically validated. void foo(){ std::vector vec = get_vec(); size_t index = get_index(); vec.at(index) = 42; }Runtime Performance Validation void must_be_fast() { using namespace

@timur_audio | https://timur.audio Widget getWidget (index i) pre (i > 0) // precondition assertion post (w: w.index() == i); // postcondition assertion Proposal: add @timur_audio | https://timur.audio Widget getWidget (index i) pre (i > 0) // precondition assertion post (w: w.index() == i); // postcondition assertion Proposal: add @timur_audio | https://timur.audio Widget getWidget (index i) pre (i > 0) // precondition assertion post (w: w.index() == i) // postcondition assertion { auto* db

the test functions below(). // struct test_item; using item_list = std::vector; using index_list = std::vector; using entropy = random_device; using prn_gen = mt19937_64; using int_dist gen(rd()); int_dist refs_index_dist(0, (int)(items.size()-1)); int_dist refs_count_dist(1, (int) refs_count); int_dist char_dist(0, 127); stopwatch sw; index_list indices; size_t index; transaction_manager gen(rd()); int_dist refs_index_dist(0, (int)(items.size()-1)); int_dist refs_count_dist(1, (int) refs_count); int_dist char_dist(0, 127); stopwatch sw; index_list indices; size_t index; transaction_manager