diff options
| -rw-r--r-- | libs/kstd/kstd/flat_map.hpp | 34 | ||||
| -rw-r--r-- | libs/kstd/kstd/flat_map.tests.cpp | 25 |
2 files changed, 48 insertions, 11 deletions
diff --git a/libs/kstd/kstd/flat_map.hpp b/libs/kstd/kstd/flat_map.hpp index dcf73392..1ed999ac 100644 --- a/libs/kstd/kstd/flat_map.hpp +++ b/libs/kstd/kstd/flat_map.hpp @@ -451,12 +451,11 @@ namespace kstd //! Get a reference to the mapped value associated with the given key. //! - //! @note This overload only participates in overload resolution if the key compare type is transparent. //! @warning This function will panic if the key is not found. //! @param x The key to look up. //! @return A reference to the mapped value. template<typename K> - requires requires(K const & k, key_type const & l) { typename key_compare::is_transparent; } + requires requires { typename key_compare::is_transparent; } [[nodiscard]] constexpr auto at(K const & x) -> mapped_type & { auto found = find(x); @@ -469,12 +468,12 @@ namespace kstd } //! Get a reference to the mapped value associated with the given key. - //! @note This overload only participates in overload resolution if the key compare type is transparent. + //! //! @warning This function will panic if the key is not found. //! @param x The key to look up. //! @return A const reference to the mapped value. template<typename K> - requires requires(K const & k, key_type const & l) { typename key_compare::is_transparent; } + requires requires { typename key_compare::is_transparent; } [[nodiscard]] auto at(K const & x) const -> mapped_type const & { auto found = find(x); @@ -486,6 +485,15 @@ namespace kstd os::panic("[kstd::flat_map] Key not found"); } + //! Get a reference to the mapped value associated with the given key, or insert a default one if none exists. + //! + //! @param key The key to look up. + [[nodiscard]] constexpr auto operator[](key_type const & key) -> mapped_type & + { + auto result = try_emplace(key); + return result.first->second; + } + //! Get an iterator to the first element. [[nodiscard]] auto begin() noexcept -> iterator { @@ -587,17 +595,16 @@ namespace kstd { auto value = value_type{std::forward<Args>(args)...}; auto found = std::ranges::lower_bound(m_containers.keys, value.first, m_comparator); + auto offset = std::distance(m_containers.keys.begin(), found); if (found != m_containers.keys.cend() && !m_comparator(value.first, *found) && !m_comparator(*found, value.first)) { - auto offset = std::distance(m_containers.keys.begin(), found); return { iterator{m_containers, offset}, false }; } - auto offset = std::distance(m_containers.keys.begin(), found); auto key_iterator = m_containers.keys.begin() + offset; auto mapped_iterator = m_containers.values.begin() + offset; @@ -620,16 +627,21 @@ namespace kstd auto try_emplace(key_type const & key, Args &&... args) -> std::pair<iterator, bool> { auto found = std::ranges::lower_bound(m_containers.keys, key, m_comparator); + auto offset = std::distance(m_containers.keys.begin(), found); + if (found != m_containers.keys.cend() && !m_comparator(*found, key) && !m_comparator(key, *found)) { - return {found, false}; + return { + iterator{m_containers, offset}, + false + }; } - auto offset = std::distance(m_containers.keys.cbegin(), found); - auto insertion_point = m_containers.value.begin() + offset; + auto key_iterator = m_containers.keys.begin() + offset; + auto mapped_iterator = m_containers.values.begin() + offset; - auto inserted_key = m_containers.keys.emplace(key); - auto inserted_mapped = m_containers.values.emplace(std::forward<Args>(args)...); + auto inserted_key = m_containers.keys.emplace(key_iterator, key); + auto inserted_mapped = m_containers.values.emplace(key_iterator, std::forward<Args>(args)...); return { iterator{m_containers, inserted_key - m_containers.keys.begin()}, diff --git a/libs/kstd/kstd/flat_map.tests.cpp b/libs/kstd/kstd/flat_map.tests.cpp index 6a1b6f2a..f0e0f813 100644 --- a/libs/kstd/kstd/flat_map.tests.cpp +++ b/libs/kstd/kstd/flat_map.tests.cpp @@ -217,6 +217,31 @@ SCENARIO("Flat Map modifiers", "[flat_map]") } } + WHEN("accessing a non-existant element using the subscript operator") + { + auto & element = map[10]; + + THEN("the element is default constructed") + { + REQUIRE(element == int{}); + } + + THEN("the element is inserted") + { + REQUIRE(map.contains(10)); + } + + AND_WHEN("assigning to that element") + { + element = 100; + + THEN("the element is assigned") + { + REQUIRE(map.at(10) == 100); + } + } + } + AND_GIVEN("a populated Flat Map") { auto other = kstd::flat_map<int, int>{}; |