zero_blob Class Reference

An efficient blob of zeroes of a given size. More...

Public Types
using	element_type = const std::byte
using	value_type = std::byte
using	index_type = size_t
using	difference_type = ptrdiff_t
using	pointer = const std::byte *
using	const_pointer = const std::byte *
using	reference = const std::byte &
using	const_reference = const std::byte &
using	iterator = const_iterator
using	reverse_iterator = std::reverse_iterator<iterator>
using	const_reverse_iterator = std::reverse_iterator<const_iterator>

Public Member Functions
constexpr	zero_blob (size_t size=0) noexcept
constexpr	zero_blob (const zero_blob &) noexcept=default
constexpr zero_blob &	operator= (const zero_blob &) noexcept=default
constexpr zero_blob	first (index_type count) const noexcept
constexpr zero_blob	last (index_type count) const noexcept
constexpr zero_blob	subspan (index_type offset, index_type count=size_t(-1)) const noexcept
constexpr index_type	size () const noexcept
constexpr index_type	size_bytes () const noexcept
constexpr bool	empty () const noexcept
constexpr reference	operator[] (index_type idx) const noexcept
constexpr reference	front () const noexcept
constexpr reference	back () const noexcept
constexpr iterator	begin () const noexcept
constexpr iterator	end () const noexcept
constexpr const_iterator	cbegin () const noexcept
constexpr const_iterator	cend () const noexcept
constexpr reverse_iterator	rbegin () const noexcept
constexpr reverse_iterator	rend () const noexcept
constexpr const_reverse_iterator	crbegin () const noexcept
constexpr const_reverse_iterator	crend () const noexcept

Detailed Description

An efficient blob of zeroes of a given size.

This class is an STL random-access container that returns 0 for all its elements. It simply stores blob size and doesn't allocate any memory.

SQLite contains optimized methods that operate on "blobs of zeroes" of a given size (e.g. sqlite3_bind_zeroblob). This class is used to pass "blobs of zeroes" to overloaded C++ methods (e.g. statement::bind(int, const zero_blob &)) to achieve the same effect in this library.