<xstd/bits/bit_ranges.hpp>

namespace xstd {
  // [ranges.syn], the from_range tag, whose counterpart for an argument's blocks is from_blocks
  struct from_blocks_t { explicit from_blocks_t() = default; };
  inline constexpr from_blocks_t from_blocks{};
}

Header	Declares
<xstd/bits/bit_ranges/from_blocks.hpp>	from_blocks, from_blocks_t