flat_set_test.cc

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/*
                          Aleph_w
 
  Data structures & Algorithms
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
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*/
 
#include <random>
#include <set>
#include <stdexcept>
#include <string>
#include <vector>
 
#include <gtest/gtest.h>
 
#include <tpl_flat_set.H>
 
using Aleph::FlatSet;
 
TEST(FlatSet, EmptySetBasics)
{
  FlatSet<int> s;
  EXPECT_TRUE(s.is_empty());
  EXPECT_EQ(s.size(), 0u);
  EXPECT_FALSE(s.contains(42));
  EXPECT_EQ(s.find(42), s.end());
  EXPECT_EQ(s.begin(), s.end());
  EXPECT_EQ(s.count(42), 0u);
}
 
TEST(FlatSet, InsertKeepsSortedOrderAndRejectsDuplicates)
{
  FlatSet<int> s;
  EXPECT_TRUE(s.insert(5).second);
  EXPECT_TRUE(s.insert(1).second);
  EXPECT_TRUE(s.insert(3).second);
  EXPECT_FALSE(s.insert(3).second);  // duplicate
 
  ASSERT_EQ(s.size(), 3u);
  EXPECT_EQ(s.nth(0), 1);
  EXPECT_EQ(s.nth(1), 3);
  EXPECT_EQ(s.nth(2), 5);
 
  // The iterator returned on a duplicate points to the existing element.
  auto [it, inserted] = s.insert(1);
  EXPECT_FALSE(inserted);
  EXPECT_EQ(*it, 1);
  EXPECT_EQ(it, s.begin());
}
 
TEST(FlatSet, InitializerListDropsDuplicates)
{
  FlatSet<int> s = {5, 1, 3, 1, 5, 5};
  ASSERT_EQ(s.size(), 3u);
  EXPECT_EQ(s.nth(0), 1);
  EXPECT_EQ(s.nth(1), 3);
  EXPECT_EQ(s.nth(2), 5);
}
 
TEST(FlatSet, RangeConstructor)
{
  const std::vector<int> v = {9, 7, 7, 8, 1};
  FlatSet<int> s(v.begin(), v.end());
  ASSERT_EQ(s.size(), 4u);
  EXPECT_TRUE(std::is_sorted(s.begin(), s.end()));
  EXPECT_TRUE(s.contains(7));
  EXPECT_TRUE(s.contains(9));
  EXPECT_FALSE(s.contains(2));
}
 
TEST(FlatSet, LookupBoundsAndEqualRange)
{
  const FlatSet<int> s = {10, 20, 30, 40};
 
  EXPECT_EQ(*s.lower_bound(20), 20);
  EXPECT_EQ(*s.lower_bound(25), 30);
  EXPECT_EQ(*s.upper_bound(20), 30);
  EXPECT_EQ(s.lower_bound(50), s.end());
  EXPECT_EQ(s.upper_bound(40), s.end());
  EXPECT_EQ(*s.lower_bound(5), 10);
 
  auto [lo, hi] = s.equal_range(30);
  ASSERT_EQ(hi - lo, 1);
  EXPECT_EQ(*lo, 30);
 
  auto [lo2, hi2] = s.equal_range(35);
  EXPECT_EQ(lo2, hi2);
}
 
TEST(FlatSet, EraseByKeyAndIterator)
{
  FlatSet<int> s = {1, 2, 3, 4, 5};
 
  EXPECT_EQ(s.erase(3), 1u);
  EXPECT_EQ(s.erase(3), 0u);  // already gone
  EXPECT_EQ(s.size(), 4u);
  EXPECT_FALSE(s.contains(3));
 
  auto it = s.find(2);
  ASSERT_NE(it, s.end());
  it = s.erase(it);
  EXPECT_EQ(*it, 4);  // element following the erased one
  EXPECT_EQ(s.size(), 3u);
 
  // Erasing an end iterator must throw out_of_range.
  EXPECT_THROW((void) s.erase(s.end()), std::out_of_range);
}
 
TEST(FlatSet, MinMaxAndCheckedAccess)
{
  FlatSet<int> s = {7, 3, 9};
  EXPECT_EQ(s.get_first(), 3);
  EXPECT_EQ(s.get_last(), 9);
  EXPECT_EQ(s.min(), 3);
  EXPECT_EQ(s.max(), 9);
  EXPECT_THROW((void) s.nth(3), std::out_of_range);
 
  const FlatSet<int> e;
  EXPECT_THROW((void) e.get_first(), std::underflow_error);
  EXPECT_THROW((void) e.get_last(), std::underflow_error);
}
 
TEST(FlatSet, AlephConventionsEmptyClearTraverse)
{
  FlatSet<int> s = {1, 2, 3};
 
  // Aleph convention: empty() clears, is_empty() tests.
  s.empty();
  EXPECT_TRUE(s.is_empty());
 
  s = {4, 5, 6, 7};
  s.clear();
  EXPECT_TRUE(s.is_empty());
 
  s = {1, 2, 3, 4};
  int sum = 0;
  EXPECT_TRUE(s.traverse([&sum] (const int &x) { sum += x; return true; }));
  EXPECT_EQ(sum, 10);
 
  // Early stop: visit only until (and including) the first even key.
  int visited = 0;
  EXPECT_FALSE(s.traverse([&visited] (const int &x)
  {
    ++visited;
    return x % 2 != 0;
  }));
  EXPECT_EQ(visited, 2);  // 1 (odd, continue), 2 (even, stop)
}
 
TEST(FlatSet, CopyMoveAndEquality)
{
  FlatSet<std::string> s = {"beta", "alpha", "gamma"};
  FlatSet<std::string> copy = s;
  EXPECT_EQ(copy, s);
 
  FlatSet<std::string> moved = std::move(copy);
  EXPECT_EQ(moved, s);
 
  moved.insert("delta");
  EXPECT_NE(moved, s);
 
  FlatSet<std::string> assigned;
  assigned = s;
  EXPECT_EQ(assigned, s);
 
  FlatSet<std::string> move_assigned;
  move_assigned = std::move(assigned);
  EXPECT_EQ(move_assigned, s);
}
 
TEST(FlatSet, CustomComparatorDescendingOrder)
{
  FlatSet<int, std::greater<int>> s = {1, 5, 3};
  EXPECT_EQ(s.nth(0), 5);
  EXPECT_EQ(s.nth(1), 3);
  EXPECT_EQ(s.nth(2), 1);
  EXPECT_TRUE(s.contains(3));
  EXPECT_FALSE(s.insert(5).second);
}
 
TEST(FlatSet, ReserveAndCapacity)
{
  FlatSet<int> s;
  s.reserve(1000);
  const size_t cap = s.capacity();
  EXPECT_GE(cap, 1000u);
  for (int i = 0; i < 1000; ++i)
    s.insert(i);
  EXPECT_EQ(s.capacity(), cap);  // no reallocation after reserve
  EXPECT_EQ(s.size(), 1000u);
}
 
TEST(FlatSet, DataIsSortedContiguousStorage)
{
  FlatSet<int> s = {4, 2, 8, 6};
  const int *p = s.data();
  ASSERT_EQ(s.size(), 4u);
  EXPECT_EQ(p[0], 2);
  EXPECT_EQ(p[3], 8);
  EXPECT_EQ(s.begin(), p);
  EXPECT_EQ(s.end(), p + 4);
}
 
TEST(FlatSet, SwapExchangesContents)
{
  FlatSet<int> a = {1, 2};
  FlatSet<int> b = {9};
  a.swap(b);
  EXPECT_EQ(a.size(), 1u);
  EXPECT_TRUE(a.contains(9));
  EXPECT_EQ(b.size(), 2u);
  EXPECT_TRUE(b.contains(1) and b.contains(2));
}
 
// Randomized parity test: FlatSet must behave exactly like std::set under
// an arbitrary interleaving of insertions, removals and lookups.
TEST(FlatSet, RandomizedParityWithStdSet)
{
  std::mt19937 rng(20260702);
  std::uniform_int_distribution<int> key_dist(0, 200);
  std::uniform_int_distribution<int> op_dist(0, 2);
 
  FlatSet<int> fs;
  std::set<int> ref;
 
  for (int step = 0; step < 4000; ++step)
    {
      const int k = key_dist(rng);
      switch (op_dist(rng))
        {
        case 0:
          EXPECT_EQ(fs.insert(k).second, ref.insert(k).second);
          break;
        case 1:
          EXPECT_EQ(fs.erase(k), ref.erase(k));
          break;
        default:
          EXPECT_EQ(fs.contains(k), ref.count(k) == 1);
          break;
        }
    }
 
  ASSERT_EQ(fs.size(), ref.size());
  size_t i = 0;
  for (const int k : ref)
    EXPECT_EQ(fs.nth(i++), k);
}