diff --git a/include/nlohmann/detail/input/binary_reader.hpp b/include/nlohmann/detail/input/binary_reader.hpp index f1b65ba54..3add2c115 100644 --- a/include/nlohmann/detail/input/binary_reader.hpp +++ b/include/nlohmann/detail/input/binary_reader.hpp @@ -42,7 +42,7 @@ enum class cbor_tag_handler_t @note from https://stackoverflow.com/a/1001328/266378 */ -static inline bool little_endianess(int num = 1) noexcept +static inline bool little_endianness(int num = 1) noexcept { return *reinterpret_cast(&num) == 1; } @@ -2341,7 +2341,7 @@ class binary_reader @return whether conversion completed - @note This function needs to respect the system's endianess, because + @note This function needs to respect the system's endianness, because bytes in CBOR, MessagePack, and UBJSON are stored in network order (big endian) and therefore need reordering on little endian systems. */ @@ -2514,8 +2514,8 @@ class binary_reader /// the number of characters read std::size_t chars_read = 0; - /// whether we can assume little endianess - const bool is_little_endian = little_endianess(); + /// whether we can assume little endianness + const bool is_little_endian = little_endianness(); /// the SAX parser json_sax_t* sax = nullptr; diff --git a/include/nlohmann/detail/output/binary_writer.hpp b/include/nlohmann/detail/output/binary_writer.hpp index 42fd50e32..23b9ff16e 100644 --- a/include/nlohmann/detail/output/binary_writer.hpp +++ b/include/nlohmann/detail/output/binary_writer.hpp @@ -1535,7 +1535,7 @@ class binary_writer @tparam OutputIsLittleEndian Set to true if output data is required to be little endian - @note This function needs to respect the system's endianess, because bytes + @note This function needs to respect the system's endianness, because bytes in CBOR, MessagePack, and UBJSON are stored in network order (big endian) and therefore need reordering on little endian systems. */ @@ -1625,8 +1625,8 @@ class binary_writer } private: - /// whether we can assume little endianess - const bool is_little_endian = little_endianess(); + /// whether we can assume little endianness + const bool is_little_endian = little_endianness(); /// the output output_adapter_t oa = nullptr; diff --git a/include/nlohmann/ordered_map.hpp b/include/nlohmann/ordered_map.hpp index cf5f133e7..51b954524 100644 --- a/include/nlohmann/ordered_map.hpp +++ b/include/nlohmann/ordered_map.hpp @@ -107,16 +107,55 @@ template , iterator erase(iterator pos) { - auto it = pos; + return erase(pos, std::next(pos)); + } - // Since we cannot move const Keys, re-construct them in place - for (auto next = it; ++next != this->end(); ++it) + iterator erase(iterator first, iterator last) + { + const auto elements_affected = std::distance(first, last); + const auto offset = std::distance(Container::begin(), first); + + // This is the start situation. We need to delete elements_affected + // elements (3 in this example: e, f, g), and need to return an + // iterator past the last deleted element (h in this example). + // Note that offset is the distance from the start of the vector + // to first. We will need this later. + + // [ a, b, c, d, e, f, g, h, i, j ] + // ^ ^ + // first last + + // Since we cannot move const Keys, we re-construct them in place. + // We start at first and re-construct (viz. copy) the elements from + // the back of the vector. Example for first iteration: + + // ,--------. + // v | destroy e and re-construct with h + // [ a, b, c, d, e, f, g, h, i, j ] + // ^ ^ + // it it + elements_affected + + for (auto it = first; std::next(it, elements_affected) != Container::end(); ++it) { - it->~value_type(); // Destroy but keep allocation - new (&*it) value_type{std::move(*next)}; + it->~value_type(); // destroy but keep allocation + new (&*it) value_type{std::move(*std::next(it, elements_affected))}; // "move" next element to it } - Container::pop_back(); - return pos; + + // [ a, b, c, d, h, i, j, h, i, j ] + // ^ ^ + // first last + + // remove the unneeded elements at the end of the vector + Container::resize(this->size() - static_cast(elements_affected)); + + // [ a, b, c, d, h, i, j ] + // ^ ^ + // first last + + // first is now pointing past the last deleted element, but we cannot + // use this iterator, because it may have been invalidated by the + // resize call. Instead, we can return begin() + offset. + return Container::begin() + offset; } size_type count(const Key& key) const diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp index 8c962dc9c..90b55c530 100644 --- a/single_include/nlohmann/json.hpp +++ b/single_include/nlohmann/json.hpp @@ -8132,7 +8132,7 @@ enum class cbor_tag_handler_t @note from https://stackoverflow.com/a/1001328/266378 */ -static inline bool little_endianess(int num = 1) noexcept +static inline bool little_endianness(int num = 1) noexcept { return *reinterpret_cast(&num) == 1; } @@ -10431,7 +10431,7 @@ class binary_reader @return whether conversion completed - @note This function needs to respect the system's endianess, because + @note This function needs to respect the system's endianness, because bytes in CBOR, MessagePack, and UBJSON are stored in network order (big endian) and therefore need reordering on little endian systems. */ @@ -10604,8 +10604,8 @@ class binary_reader /// the number of characters read std::size_t chars_read = 0; - /// whether we can assume little endianess - const bool is_little_endian = little_endianess(); + /// whether we can assume little endianness + const bool is_little_endian = little_endianness(); /// the SAX parser json_sax_t* sax = nullptr; @@ -14741,7 +14741,7 @@ class binary_writer @tparam OutputIsLittleEndian Set to true if output data is required to be little endian - @note This function needs to respect the system's endianess, because bytes + @note This function needs to respect the system's endianness, because bytes in CBOR, MessagePack, and UBJSON are stored in network order (big endian) and therefore need reordering on little endian systems. */ @@ -14831,8 +14831,8 @@ class binary_writer } private: - /// whether we can assume little endianess - const bool is_little_endian = little_endianess(); + /// whether we can assume little endianness + const bool is_little_endian = little_endianness(); /// the output output_adapter_t oa = nullptr; @@ -17033,16 +17033,55 @@ template , iterator erase(iterator pos) { - auto it = pos; + return erase(pos, std::next(pos)); + } - // Since we cannot move const Keys, re-construct them in place - for (auto next = it; ++next != this->end(); ++it) + iterator erase(iterator first, iterator last) + { + const auto elements_affected = std::distance(first, last); + const auto offset = std::distance(Container::begin(), first); + + // This is the start situation. We need to delete elements_affected + // elements (3 in this example: e, f, g), and need to return an + // iterator past the last deleted element (h in this example). + // Note that offset is the distance from the start of the vector + // to first. We will need this later. + + // [ a, b, c, d, e, f, g, h, i, j ] + // ^ ^ + // first last + + // Since we cannot move const Keys, we re-construct them in place. + // We start at first and re-construct (viz. copy) the elements from + // the back of the vector. Example for first iteration: + + // ,--------. + // v | destroy e and re-construct with h + // [ a, b, c, d, e, f, g, h, i, j ] + // ^ ^ + // it it + elements_affected + + for (auto it = first; std::next(it, elements_affected) != Container::end(); ++it) { - it->~value_type(); // Destroy but keep allocation - new (&*it) value_type{std::move(*next)}; + it->~value_type(); // destroy but keep allocation + new (&*it) value_type{std::move(*std::next(it, elements_affected))}; // "move" next element to it } - Container::pop_back(); - return pos; + + // [ a, b, c, d, h, i, j, h, i, j ] + // ^ ^ + // first last + + // remove the unneeded elements at the end of the vector + Container::resize(this->size() - static_cast(elements_affected)); + + // [ a, b, c, d, h, i, j ] + // ^ ^ + // first last + + // first is now pointing past the last deleted element, but we cannot + // use this iterator, because it may have been invalidated by the + // resize call. Instead, we can return begin() + offset. + return Container::begin() + offset; } size_type count(const Key& key) const diff --git a/test/src/unit-ordered_map.cpp b/test/src/unit-ordered_map.cpp index 7a23e36fb..a8f2850c8 100644 --- a/test/src/unit-ordered_map.cpp +++ b/test/src/unit-ordered_map.cpp @@ -210,6 +210,45 @@ TEST_CASE("ordered_map") ++it2; CHECK(it2 == om.end()); } + + SECTION("with iterator pair") + { + SECTION("range in the middle") + { + // need more elements + om["vier"] = "four"; + om["fünf"] = "five"; + + // delete "zwei" and "drei" + auto it = om.erase(om.begin() + 1, om.begin() + 3); + CHECK(it->first == "vier"); + CHECK(om.size() == 3); + } + + SECTION("range at the beginning") + { + // need more elements + om["vier"] = "four"; + om["fünf"] = "five"; + + // delete "eins" and "zwei" + auto it = om.erase(om.begin(), om.begin() + 2); + CHECK(it->first == "drei"); + CHECK(om.size() == 3); + } + + SECTION("range at the end") + { + // need more elements + om["vier"] = "four"; + om["fünf"] = "five"; + + // delete "vier" and "fünf" + auto it = om.erase(om.begin() + 3, om.end()); + CHECK(it == om.end()); + CHECK(om.size() == 3); + } + } } SECTION("count") diff --git a/test/src/unit-regression2.cpp b/test/src/unit-regression2.cpp index f0c4ef451..b2f2a7dc3 100644 --- a/test/src/unit-regression2.cpp +++ b/test/src/unit-regression2.cpp @@ -746,6 +746,23 @@ TEST_CASE("regression tests 2") std::vector foo; j.get_to(foo); } + + SECTION("issue #3108 - ordered_json doesn't support range based erase") + { + ordered_json j = {1, 2, 2, 4}; + + auto last = std::unique(j.begin(), j.end()); + j.erase(last, j.end()); + + CHECK(j.dump() == "[1,2,4]"); + + j.erase(std::remove_if(j.begin(), j.end(), [](const ordered_json & val) + { + return val == 2; + }), j.end()); + + CHECK(j.dump() == "[1,4]"); + } } DOCTEST_CLANG_SUPPRESS_WARNING_POP