robin-map：快速hash_map和hash_set

#include <cstdint>
#include <iostream>
#include <string>
#include <tsl/robin_map.h>
#include <tsl/robin_set.h>
int main() {
    tsl::robin_map<std::string, int> map = {{"a", 1}, {"b", 2}};
    map["c"] = 3;
    map["d"] = 4;
    map.insert({"e", 5});
    map.erase("b");
    for(auto it = map.begin(); it != map.end(); ++it) {
        //it->second += 2; // Not valid.
        it.value() += 2;
    // {d, 6} {a, 3} {e, 7} {c, 5}
    for(const auto& key_value : map) {
        std::cout << "{" << key_value.first << ", " << key_value.second << "}" << std::endl;
    if(map.find("a") != map.end()) {
        std::cout << "Found \"a\"." << std::endl;
    const std::size_t precalculated_hash = std::hash<std::string>()("a");
    // If we already know the hash beforehand, we can pass it in parameter to speed-up lookups.
    if(map.find("a", precalculated_hash) != map.end()) {
        std::cout << "Found \"a\" with hash " << precalculated_hash << "." << std::endl;
     * Calculating the hash and comparing two std::string may be slow. 
     * We can store the hash of each std::string in the hash map to make 
     * the inserts and lookups faster by setting StoreHash to true.
    tsl::robin_map<std::string, int, std::hash<std::string>, 
                   std::equal_to<std::string>,
                   std::allocator<std::pair<std::string, int>>,
                   true> map2;
    map2["a"] = 1;
    map2["b"] = 2;
    // {a, 1} {b, 2}
    for(const auto& key_value : map2) {
        std::cout << "{" << key_value.first << ", " << key_value.second << "}" << std::endl;
    tsl::robin_set<int> set;
    set.insert({1, 9, 0});
    set.insert({2, -1, 9});