Update rng.hpp

.github/workflows/macos.yml

@@ -17,7 +17,7 @@ jobs:
             {
               cxx: $(brew --prefix llvm@15)/bin/clang++,
               pkgs: llvm@15 gcc@11,
-              extra-flags: "-femulated-tls -stdlib=libstdc++ -stdlib++-isystem $(brew --prefix gcc@11)/include/c++/11 -cxx-isystem $(brew --prefix gcc@11)/include/c++/11/aarch64-apple-darwin23",
+              extra-flags: "-femulated-tls -stdlib=libstdc++ -stdlib++-isystem $(brew --prefix gcc@11)/include/c++/11 -cxx-isystem $(brew --prefix gcc@11)/include/c++/11/aarch64-apple-darwin23 -fsanitize=address -g -fno-omit-frame-pointer",
               linker-flags: "-L$(brew --prefix gcc@11)/lib/gcc/11"
             }
         ]

src/utility/rng.hpp

@@ -29,6 +29,8 @@
 #include <cstddef>
 #include <concepts>
 
+#include <iostream>
+
 
 #ifndef GAPP_SEED
 #   define GAPP_SEED 0x3da99432ab975d26LL
@@ -457,6 +459,8 @@ namespace gapp::rng
     template<std::integral IntType>
     GAPP_NOINLINE small_vector<IntType> sampleUniqueSet(IntType lbound, IntType ubound, size_t count)
     {
+        std::cout << "sampleUniqueSet\n";
+
         std::unordered_set<IntType> selected(count);
         small_vector<IntType> numbers(count);
 
@@ -477,20 +481,29 @@ namespace gapp::rng
     {
         const size_t range_len = detail::range_length(lbound, ubound);
 
+        std::cout << "Sample unique lbound: " << lbound << ", ubound: " << ubound << ", count: " << count << "\n";
+
         GAPP_ASSERT(ubound >= lbound);
         GAPP_ASSERT(range_len >= count);
 
-        const bool select_many = (count > 0.6 * range_len);
-        const bool huge_range  = (range_len >= 65536);
+        const bool select_many = std::cmp_greater_equal(count, size_t(0.6 * range_len));
+        const bool huge_range = std::cmp_greater_equal(range_len, 65536);
 
-        if (huge_range) [[unlikely]] return rng::sampleUniqueSet(lbound, ubound, count);
+        std::cout << "Range len: " << range_len << ", huge_range: " << huge_range << "\n";
+        std::cout << "select many: " << select_many << "\n";
+
+        if (huge_range) return rng::sampleUniqueSet(lbound, ubound, count);
+
+        std::cout << "Sample unique small\n";
 
         small_vector<IntType> numbers(count);
 
         thread_local detail::dynamic_bitset is_selected;
         is_selected.resize(range_len);
         is_selected.fill(select_many);
 
+        std::cout << "Allocated\n";
+
         if (!select_many)
         {
             IntType limit = ubound - detail::promoted_t<IntType>(count);

src/utility/small_vector.hpp

@@ -302,18 +302,17 @@ namespace gapp::detail
     struct small_vector_buffer
     {
     public:
-        constexpr small_vector_buffer() noexcept {};    // NOLINT(*default)
-        constexpr ~small_vector_buffer() noexcept {};   // NOLINT(*default)
+        small_vector_buffer() = default;
 
-        constexpr auto begin() noexcept { return std::begin(data_); }
-        constexpr auto begin() const noexcept { return std::begin(data_); }
+        auto begin() noexcept { return std::launder(reinterpret_cast<T*>(&data_)); }
+        auto begin() const noexcept { return std::launder(reinterpret_cast<const T*>(&data_)); }
 
-        constexpr auto end() noexcept { return std::end(data_); }
-        constexpr auto end() const noexcept { return std::end(data_); }
+        auto end() noexcept { return begin() + Size; }
+        auto end() const noexcept { return begin() + Size; }
 
-        constexpr std::size_t size() const noexcept { return std::size(data_); }
+        constexpr std::size_t size() const noexcept { return Size; }
     private:
-        union { char dummy_ = {}; T data_[Size]; }; // NOLINT(*arrays)
+        alignas(T) unsigned char data_[Size * sizeof(T)] = {}; // NOLINT(*arrays)
     };
 
 
@@ -890,9 +889,6 @@ namespace gapp
         }
 
     private:
-        static constexpr std::size_t alignment = std::max(alignof(T), detail::cache_line_size);
-
-        alignas(alignment)
         GAPP_NO_UNIQUE_ADDRESS detail::small_vector_buffer<T, Size> buffer_;
         pointer first_      = nullptr;
         pointer last_       = nullptr;

test/unit/small_vector.cpp

@@ -97,7 +97,6 @@ TEST_CASE("small_vector_size", "[object_layout][!mayfail]") // fails under clang
     STATIC_REQUIRE(std::is_standard_layout_v<small_vector<int>>);
 
     CHECK(sizeof(small_vector<int>) == detail::cache_line_size);
-    CHECK(alignof(small_vector<int>) == detail::cache_line_size);
 }