diff --git a/mdbx.h++ b/mdbx.h++ index d42b5942..74373039 100644 --- a/mdbx.h++ +++ b/mdbx.h++ @@ -3180,6 +3180,92 @@ struct pair_result : public pair { } }; +template +struct buffer_pair_spec { + using buffer_type = buffer; + using allocator_type = typename buffer_type::allocator_type; + using allocator_traits = typename buffer_type::allocator_traits; + using reservation_policy = CAPACITY_POLICY; + using stl_pair = ::std::pair; + buffer_type key, value; + + MDBX_CXX20_CONSTEXPR buffer_pair_spec() noexcept = default; + MDBX_CXX20_CONSTEXPR + buffer_pair_spec(const allocator_type &allocator) noexcept + : key(allocator), value(allocator) {} + + buffer_pair_spec(const buffer_type &key, const buffer_type &value, + const allocator_type &allocator = allocator_type()) + : key(key, allocator), value(value, allocator) {} + buffer_pair_spec(const buffer_type &key, const buffer_type &value, + bool make_reference, + const allocator_type &allocator = allocator_type()) + : key(key, make_reference, allocator), + value(value, make_reference, allocator) {} + + buffer_pair_spec(const stl_pair &pair, + const allocator_type &allocator = allocator_type()) + : buffer_pair_spec(pair.first, pair.second, allocator) {} + buffer_pair_spec(const stl_pair &pair, bool make_reference, + const allocator_type &allocator = allocator_type()) + : buffer_pair_spec(pair.first, pair.second, make_reference, allocator) {} + + buffer_pair_spec(const slice &key, const slice &value, + const allocator_type &allocator = allocator_type()) + : key(key, allocator), value(value, allocator) {} + buffer_pair_spec(const slice &key, const slice &value, bool make_reference, + const allocator_type &allocator = allocator_type()) + : key(key, make_reference, allocator), + value(value, make_reference, allocator) {} + + buffer_pair_spec(const pair &pair, + const allocator_type &allocator = allocator_type()) + : buffer_pair_spec(pair.key, pair.value, allocator) {} + buffer_pair_spec(const pair &pair, bool make_reference, + const allocator_type &allocator = allocator_type()) + : buffer_pair_spec(pair.key, pair.value, make_reference, allocator) {} + + buffer_pair_spec(const txn &txn, const slice &key, const slice &value, + const allocator_type &allocator = allocator_type()) + : key(txn, key, allocator), value(txn, value, allocator) {} + buffer_pair_spec(const txn &txn, const pair &pair, + const allocator_type &allocator = allocator_type()) + : buffer_pair_spec(txn, pair.key, pair.value, allocator) {} + + buffer_pair_spec(buffer_type &&key, buffer_type &&value) noexcept( + buffer_type::move_assign_alloc::is_nothrow()) + : key(::std::move(key)), value(::std::move(value)) {} + buffer_pair_spec(buffer_pair_spec &&pair) noexcept( + buffer_type::move_assign_alloc::is_nothrow()) + : buffer_pair_spec(::std::move(pair.key), ::std::move(pair.value)) {} + + /// \brief Checks whether data chunk stored inside the buffers both, otherwise + /// at least one of buffers just refers to data located outside. + MDBX_NOTHROW_PURE_FUNCTION MDBX_CXX20_CONSTEXPR bool + is_freestanding() const noexcept { + return key.is_freestanding() && value.is_freestanding(); + } + /// \brief Checks whether one of the buffers just refers to data located + /// outside the buffer, rather than stores it. + MDBX_NOTHROW_PURE_FUNCTION MDBX_CXX20_CONSTEXPR bool + is_reference() const noexcept { + return key.is_reference() || value.is_reference(); + } + /// \brief Makes buffers owning the data. + /// \details If buffer refers to an external data, then makes it the owner + /// of clone by allocating storage and copying the data. + void make_freestanding() { + key.make_freestanding(); + value.make_freestanding(); + } + + operator pair() const noexcept { return pair(key, value); } +}; + +template +using buffer_pair = buffer_pair_spec; + /// end of cxx_data @} //------------------------------------------------------------------------------