commit 572b5c7bd535e31983601264a813db9b6cf55915
Author: caiowakamatsu <caiodcw@gmail.com>
Date:   Wed Aug 26 22:07:13 2026 -0300

    initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..fc17777
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+build/*
+run/*
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..075df17
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 4.2.0)
+
+set(CMAKE_EXPERIMENTAL_CXX_IMPORT_STD "f35a9ac6-8463-4d38-8eec-5d6008153e7d")
+set(CMAKE_CXX_STANDARD 26)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_MODULE_STD ON)
+set(CMAKE_CXX_STDLIB_MODULES_JSON "$ENV{HOME}/.local/gcc16/libstdc++.modules.json")
+
+project(1brc)
+set(CMAKE_CXX_STANDARD 26)
+
+add_subdirectory(source)
+add_subdirectory(generate)
diff --git a/generate/CMakeLists.txt b/generate/CMakeLists.txt
new file mode 100644
index 0000000..6bcece9
--- /dev/null
+++ b/generate/CMakeLists.txt
@@ -0,0 +1,10 @@
+add_executable(generate_measurements
+	main.cxx
+)
+target_sources(generate_measurements
+	PUBLIC
+		FILE_SET gen_measurements_modules TYPE CXX_MODULES FILES
+		#		util/logger.ixx
+)
+
+target_compile_options(generate_measurements PUBLIC -freflection -fcontracts -fcontract-evaluation-semantic=enforce)
diff --git a/generate/main.cxx b/generate/main.cxx
new file mode 100644
index 0000000..7aab09c
--- /dev/null
+++ b/generate/main.cxx
@@ -0,0 +1,499 @@
+// generate_measurements.cpp
+//
+// Simple standalone generator for 1BRC-style data, no Java/Maven needed.
+//
+// Build:
+//   g++ -O2 -o generate_measurements generate_measurements.cpp
+//
+// Run:
+//   ./generate_measurements 1000000000 > measurements.txt
+//   (defaults to 1,000,000,000 rows if no argument given)
+//
+// Output format matches the original challenge:
+//   <station name>;<temperature to 1 decimal place>
+//
+// Uses the real 413 station names + mean temperatures from the official
+// challenge's CreateMeasurements.java. Temperatures are generated as
+// station_mean + gaussian noise, clamped to [-99.9, 99.9] — the same
+// approach the official generator uses.
+//
+// Note: station names include UTF-8 characters (e.g. "Zürich", "Abéché"),
+// so save/compile this file as UTF-8.
+
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <random>
+#include <string>
+#include <vector>
+
+int main(int argc, char **argv) {
+  long long numRows = 1'000'000'000LL;
+  if (argc > 1) {
+    numRows = std::atoll(argv[1]);
+    if (numRows <= 0) {
+      std::fprintf(stderr, "Invalid row count: %s\n", argv[1]);
+      return 1;
+    }
+  }
+
+  // Station name -> approximate mean annual temperature (Celsius).
+  // A representative subset of real-world locations/climates.
+  // Station name -> average temperature (Celsius), taken directly from
+  // the official 1BRC repo's CreateMeasurements.java (413 real stations).
+  static const std::vector<std::pair<const char *, double>> stations = {
+      {"Abha", 18.0},
+      {"Abidjan", 26.0},
+      {"Abéché", 29.4},
+      {"Accra", 26.4},
+      {"Addis Ababa", 16.0},
+      {"Adelaide", 17.3},
+      {"Aden", 29.1},
+      {"Ahvaz", 25.4},
+      {"Albuquerque", 14.0},
+      {"Alexandra", 11.0},
+      {"Alexandria", 20.0},
+      {"Algiers", 18.2},
+      {"Alice Springs", 21.0},
+      {"Almaty", 10.0},
+      {"Amsterdam", 10.2},
+      {"Anadyr", -6.9},
+      {"Anchorage", 2.8},
+      {"Andorra la Vella", 9.8},
+      {"Ankara", 12.0},
+      {"Antananarivo", 17.9},
+      {"Antsiranana", 25.2},
+      {"Arkhangelsk", 1.3},
+      {"Ashgabat", 17.1},
+      {"Asmara", 15.6},
+      {"Assab", 30.5},
+      {"Astana", 3.5},
+      {"Athens", 19.2},
+      {"Atlanta", 17.0},
+      {"Auckland", 15.2},
+      {"Austin", 20.7},
+      {"Baghdad", 22.77},
+      {"Baguio", 19.5},
+      {"Baku", 15.1},
+      {"Baltimore", 13.1},
+      {"Bamako", 27.8},
+      {"Bangkok", 28.6},
+      {"Bangui", 26.0},
+      {"Banjul", 26.0},
+      {"Barcelona", 18.2},
+      {"Bata", 25.1},
+      {"Batumi", 14.0},
+      {"Beijing", 12.9},
+      {"Beirut", 20.9},
+      {"Belgrade", 12.5},
+      {"Belize City", 26.7},
+      {"Benghazi", 19.9},
+      {"Bergen", 7.7},
+      {"Berlin", 10.3},
+      {"Bilbao", 14.7},
+      {"Birao", 26.5},
+      {"Bishkek", 11.3},
+      {"Bissau", 27.0},
+      {"Blantyre", 22.2},
+      {"Bloemfontein", 15.6},
+      {"Boise", 11.4},
+      {"Bordeaux", 14.2},
+      {"Bosaso", 30.0},
+      {"Boston", 10.9},
+      {"Bouaké", 26.0},
+      {"Bratislava", 10.5},
+      {"Brazzaville", 25.0},
+      {"Bridgetown", 27.0},
+      {"Brisbane", 21.4},
+      {"Brussels", 10.5},
+      {"Bucharest", 10.8},
+      {"Budapest", 11.3},
+      {"Bujumbura", 23.8},
+      {"Bulawayo", 18.9},
+      {"Burnie", 13.1},
+      {"Busan", 15.0},
+      {"Cabo San Lucas", 23.9},
+      {"Cairns", 25.0},
+      {"Cairo", 21.4},
+      {"Calgary", 4.4},
+      {"Canberra", 13.1},
+      {"Cape Town", 16.2},
+      {"Changsha", 17.4},
+      {"Charlotte", 16.1},
+      {"Chiang Mai", 25.8},
+      {"Chicago", 9.8},
+      {"Chihuahua", 18.6},
+      {"Chișinău", 10.2},
+      {"Chittagong", 25.9},
+      {"Chongqing", 18.6},
+      {"Christchurch", 12.2},
+      {"City of San Marino", 11.8},
+      {"Colombo", 27.4},
+      {"Columbus", 11.7},
+      {"Conakry", 26.4},
+      {"Copenhagen", 9.1},
+      {"Cotonou", 27.2},
+      {"Cracow", 9.3},
+      {"Da Lat", 17.9},
+      {"Da Nang", 25.8},
+      {"Dakar", 24.0},
+      {"Dallas", 19.0},
+      {"Damascus", 17.0},
+      {"Dampier", 26.4},
+      {"Dar es Salaam", 25.8},
+      {"Darwin", 27.6},
+      {"Denpasar", 23.7},
+      {"Denver", 10.4},
+      {"Detroit", 10.0},
+      {"Dhaka", 25.9},
+      {"Dikson", -11.1},
+      {"Dili", 26.6},
+      {"Djibouti", 29.9},
+      {"Dodoma", 22.7},
+      {"Dolisie", 24.0},
+      {"Douala", 26.7},
+      {"Dubai", 26.9},
+      {"Dublin", 9.8},
+      {"Dunedin", 11.1},
+      {"Durban", 20.6},
+      {"Dushanbe", 14.7},
+      {"Edinburgh", 9.3},
+      {"Edmonton", 4.2},
+      {"El Paso", 18.1},
+      {"Entebbe", 21.0},
+      {"Erbil", 19.5},
+      {"Erzurum", 5.1},
+      {"Fairbanks", -2.3},
+      {"Fianarantsoa", 17.9},
+      {"Flores,  Petén", 26.4},
+      {"Frankfurt", 10.6},
+      {"Fresno", 17.9},
+      {"Fukuoka", 17.0},
+      {"Gabès", 19.5},
+      {"Gaborone", 21.0},
+      {"Gagnoa", 26.0},
+      {"Gangtok", 15.2},
+      {"Garissa", 29.3},
+      {"Garoua", 28.3},
+      {"George Town", 27.9},
+      {"Ghanzi", 21.4},
+      {"Gjoa Haven", -14.4},
+      {"Guadalajara", 20.9},
+      {"Guangzhou", 22.4},
+      {"Guatemala City", 20.4},
+      {"Halifax", 7.5},
+      {"Hamburg", 9.7},
+      {"Hamilton", 13.8},
+      {"Hanga Roa", 20.5},
+      {"Hanoi", 23.6},
+      {"Harare", 18.4},
+      {"Harbin", 5.0},
+      {"Hargeisa", 21.7},
+      {"Hat Yai", 27.0},
+      {"Havana", 25.2},
+      {"Helsinki", 5.9},
+      {"Heraklion", 18.9},
+      {"Hiroshima", 16.3},
+      {"Ho Chi Minh City", 27.4},
+      {"Hobart", 12.7},
+      {"Hong Kong", 23.3},
+      {"Honiara", 26.5},
+      {"Honolulu", 25.4},
+      {"Houston", 20.8},
+      {"Ifrane", 11.4},
+      {"Indianapolis", 11.8},
+      {"Iqaluit", -9.3},
+      {"Irkutsk", 1.0},
+      {"Istanbul", 13.9},
+      {"İzmir", 17.9},
+      {"Jacksonville", 20.3},
+      {"Jakarta", 26.7},
+      {"Jayapura", 27.0},
+      {"Jerusalem", 18.3},
+      {"Johannesburg", 15.5},
+      {"Jos", 22.8},
+      {"Juba", 27.8},
+      {"Kabul", 12.1},
+      {"Kampala", 20.0},
+      {"Kandi", 27.7},
+      {"Kankan", 26.5},
+      {"Kano", 26.4},
+      {"Kansas City", 12.5},
+      {"Karachi", 26.0},
+      {"Karonga", 24.4},
+      {"Kathmandu", 18.3},
+      {"Khartoum", 29.9},
+      {"Kingston", 27.4},
+      {"Kinshasa", 25.3},
+      {"Kolkata", 26.7},
+      {"Kuala Lumpur", 27.3},
+      {"Kumasi", 26.0},
+      {"Kunming", 15.7},
+      {"Kuopio", 3.4},
+      {"Kuwait City", 25.7},
+      {"Kyiv", 8.4},
+      {"Kyoto", 15.8},
+      {"La Ceiba", 26.2},
+      {"La Paz", 23.7},
+      {"Lagos", 26.8},
+      {"Lahore", 24.3},
+      {"Lake Havasu City", 23.7},
+      {"Lake Tekapo", 8.7},
+      {"Las Palmas de Gran Canaria", 21.2},
+      {"Las Vegas", 20.3},
+      {"Launceston", 13.1},
+      {"Lhasa", 7.6},
+      {"Libreville", 25.9},
+      {"Lisbon", 17.5},
+      {"Livingstone", 21.8},
+      {"Ljubljana", 10.9},
+      {"Lodwar", 29.3},
+      {"Lomé", 26.9},
+      {"London", 11.3},
+      {"Los Angeles", 18.6},
+      {"Louisville", 13.9},
+      {"Luanda", 25.8},
+      {"Lubumbashi", 20.8},
+      {"Lusaka", 19.9},
+      {"Luxembourg City", 9.3},
+      {"Lviv", 7.8},
+      {"Lyon", 12.5},
+      {"Madrid", 15.0},
+      {"Mahajanga", 26.3},
+      {"Makassar", 26.7},
+      {"Makurdi", 26.0},
+      {"Malabo", 26.3},
+      {"Malé", 28.0},
+      {"Managua", 27.3},
+      {"Manama", 26.5},
+      {"Mandalay", 28.0},
+      {"Mango", 28.1},
+      {"Manila", 28.4},
+      {"Maputo", 22.8},
+      {"Marrakesh", 19.6},
+      {"Marseille", 15.8},
+      {"Maun", 22.4},
+      {"Medan", 26.5},
+      {"Mek'ele", 22.7},
+      {"Melbourne", 15.1},
+      {"Memphis", 17.2},
+      {"Mexicali", 23.1},
+      {"Mexico City", 17.5},
+      {"Miami", 24.9},
+      {"Milan", 13.0},
+      {"Milwaukee", 8.9},
+      {"Minneapolis", 7.8},
+      {"Minsk", 6.7},
+      {"Mogadishu", 27.1},
+      {"Mombasa", 26.3},
+      {"Monaco", 16.4},
+      {"Moncton", 6.1},
+      {"Monterrey", 22.3},
+      {"Montreal", 6.8},
+      {"Moscow", 5.8},
+      {"Mumbai", 27.1},
+      {"Murmansk", 0.6},
+      {"Muscat", 28.0},
+      {"Mzuzu", 17.7},
+      {"N'Djamena", 28.3},
+      {"Naha", 23.1},
+      {"Nairobi", 17.8},
+      {"Nakhon Ratchasima", 27.3},
+      {"Napier", 14.6},
+      {"Napoli", 15.9},
+      {"Nashville", 15.4},
+      {"Nassau", 24.6},
+      {"Ndola", 20.3},
+      {"New Delhi", 25.0},
+      {"New Orleans", 20.7},
+      {"New York City", 12.9},
+      {"Ngaoundéré", 22.0},
+      {"Niamey", 29.3},
+      {"Nicosia", 19.7},
+      {"Niigata", 13.9},
+      {"Nouadhibou", 21.3},
+      {"Nouakchott", 25.7},
+      {"Novosibirsk", 1.7},
+      {"Nuuk", -1.4},
+      {"Odesa", 10.7},
+      {"Odienné", 26.0},
+      {"Oklahoma City", 15.9},
+      {"Omaha", 10.6},
+      {"Oranjestad", 28.1},
+      {"Oslo", 5.7},
+      {"Ottawa", 6.6},
+      {"Ouagadougou", 28.3},
+      {"Ouahigouya", 28.6},
+      {"Ouarzazate", 18.9},
+      {"Oulu", 2.7},
+      {"Palembang", 27.3},
+      {"Palermo", 18.5},
+      {"Palm Springs", 24.5},
+      {"Palmerston North", 13.2},
+      {"Panama City", 28.0},
+      {"Parakou", 26.8},
+      {"Paris", 12.3},
+      {"Perth", 18.7},
+      {"Petropavlovsk-Kamchatsky", 1.9},
+      {"Philadelphia", 13.2},
+      {"Phnom Penh", 28.3},
+      {"Phoenix", 23.9},
+      {"Pittsburgh", 10.8},
+      {"Podgorica", 15.3},
+      {"Pointe-Noire", 26.1},
+      {"Pontianak", 27.7},
+      {"Port Moresby", 26.9},
+      {"Port Sudan", 28.4},
+      {"Port Vila", 24.3},
+      {"Port-Gentil", 26.0},
+      {"Portland (OR)", 12.4},
+      {"Porto", 15.7},
+      {"Prague", 8.4},
+      {"Praia", 24.4},
+      {"Pretoria", 18.2},
+      {"Pyongyang", 10.8},
+      {"Rabat", 17.2},
+      {"Rangpur", 24.4},
+      {"Reggane", 28.3},
+      {"Reykjavík", 4.3},
+      {"Riga", 6.2},
+      {"Riyadh", 26.0},
+      {"Rome", 15.2},
+      {"Roseau", 26.2},
+      {"Rostov-on-Don", 9.9},
+      {"Sacramento", 16.3},
+      {"Saint Petersburg", 5.8},
+      {"Saint-Pierre", 5.7},
+      {"Salt Lake City", 11.6},
+      {"San Antonio", 20.8},
+      {"San Diego", 17.8},
+      {"San Francisco", 14.6},
+      {"San Jose", 16.4},
+      {"San José", 22.6},
+      {"San Juan", 27.2},
+      {"San Salvador", 23.1},
+      {"Sana'a", 20.0},
+      {"Santo Domingo", 25.9},
+      {"Sapporo", 8.9},
+      {"Sarajevo", 10.1},
+      {"Saskatoon", 3.3},
+      {"Seattle", 11.3},
+      {"Ségou", 28.0},
+      {"Seoul", 12.5},
+      {"Seville", 19.2},
+      {"Shanghai", 16.7},
+      {"Singapore", 27.0},
+      {"Skopje", 12.4},
+      {"Sochi", 14.2},
+      {"Sofia", 10.6},
+      {"Sokoto", 28.0},
+      {"Split", 16.1},
+      {"St. John's", 5.0},
+      {"St. Louis", 13.9},
+      {"Stockholm", 6.6},
+      {"Surabaya", 27.1},
+      {"Suva", 25.6},
+      {"Suwałki", 7.2},
+      {"Sydney", 17.7},
+      {"Tabora", 23.0},
+      {"Tabriz", 12.6},
+      {"Taipei", 23.0},
+      {"Tallinn", 6.4},
+      {"Tamale", 27.9},
+      {"Tamanrasset", 21.7},
+      {"Tampa", 22.9},
+      {"Tashkent", 14.8},
+      {"Tauranga", 14.8},
+      {"Tbilisi", 12.9},
+      {"Tegucigalpa", 21.7},
+      {"Tehran", 17.0},
+      {"Tel Aviv", 20.0},
+      {"Thessaloniki", 16.0},
+      {"Thiès", 24.0},
+      {"Tijuana", 17.8},
+      {"Timbuktu", 28.0},
+      {"Tirana", 15.2},
+      {"Toamasina", 23.4},
+      {"Tokyo", 15.4},
+      {"Toliara", 24.1},
+      {"Toluca", 12.4},
+      {"Toronto", 9.4},
+      {"Tripoli", 20.0},
+      {"Tromsø", 2.9},
+      {"Tucson", 20.9},
+      {"Tunis", 18.4},
+      {"Ulaanbaatar", -0.4},
+      {"Upington", 20.4},
+      {"Ürümqi", 7.4},
+      {"Vaduz", 10.1},
+      {"Valencia", 18.3},
+      {"Valletta", 18.8},
+      {"Vancouver", 10.4},
+      {"Veracruz", 25.4},
+      {"Vienna", 10.4},
+      {"Vientiane", 25.9},
+      {"Villahermosa", 27.1},
+      {"Vilnius", 6.0},
+      {"Virginia Beach", 15.8},
+      {"Vladivostok", 4.9},
+      {"Warsaw", 8.5},
+      {"Washington, D.C.", 14.6},
+      {"Wau", 27.8},
+      {"Wellington", 12.9},
+      {"Whitehorse", -0.1},
+      {"Wichita", 13.9},
+      {"Willemstad", 28.0},
+      {"Winnipeg", 3.0},
+      {"Wrocław", 9.6},
+      {"Xi'an", 14.1},
+      {"Yakutsk", -8.8},
+      {"Yangon", 27.5},
+      {"Yaoundé", 23.8},
+      {"Yellowknife", -4.3},
+      {"Yerevan", 12.4},
+      {"Yinchuan", 9.0},
+      {"Zagreb", 10.7},
+      {"Zanzibar City", 26.0},
+      {"Zürich", 9.3}};
+
+  std::mt19937 rng(std::random_device{}());
+  std::uniform_int_distribution<size_t> stationPicker(0, stations.size() - 1);
+
+  // Use a big stdio buffer + manual formatting for speed, since default
+  // cout/printf per-line for a billion rows would otherwise dominate runtime.
+  constexpr size_t BUF_SIZE = 1 << 20; // 1 MB
+  std::vector<char> buffer(BUF_SIZE);
+  size_t bufPos = 0;
+
+  auto flushBuffer = [&]() {
+    std::fwrite(buffer.data(), 1, bufPos, stdout);
+    bufPos = 0;
+  };
+
+  auto writeStr = [&](const char *s, size_t len) {
+    if (bufPos + len > BUF_SIZE)
+      flushBuffer();
+    std::memcpy(buffer.data() + bufPos, s, len);
+    bufPos += len;
+  };
+
+  for (long long i = 0; i < numRows; ++i) {
+    size_t idx = stationPicker(rng);
+    const char *name = stations[idx].first;
+    double mean = stations[idx].second;
+
+    std::normal_distribution<double> tempDist(mean, 8.0);
+    double temp = tempDist(rng);
+    if (temp > 99.9)
+      temp = 99.9;
+    if (temp < -99.9)
+      temp = -99.9;
+
+    char line[160]; // headroom for longer UTF-8 station names
+    int len = std::snprintf(line, sizeof(line), "%s;%.1f\n", name, temp);
+    writeStr(line, static_cast<size_t>(len));
+  }
+
+  flushBuffer();
+  return 0;
+}
diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
new file mode 100644
index 0000000..1b00cee
--- /dev/null
+++ b/source/CMakeLists.txt
@@ -0,0 +1,11 @@
+add_executable(1brc
+	main.cxx
+)
+target_sources(1brc
+	PUBLIC
+		FILE_SET 1brc_modules TYPE CXX_MODULES FILES
+		#		util/logger.ixx
+)
+
+target_compile_options(1brc PUBLIC -freflection -fcontracts -fcontract-evaluation-semantic=enforce)
+
diff --git a/source/main.cxx b/source/main.cxx
new file mode 100644
index 0000000..1593f68
--- /dev/null
+++ b/source/main.cxx
@@ -0,0 +1,3 @@
+import std;
+
+auto main() -> int { std::println("hello world"); }