std::span<T,Extent>::subspan (3) - Linux Manuals

std::span<T,Extent>::subspan: std::span<T,Extent>::subspan

NAME

std::span<T,Extent>::subspan - std::span<T,Extent>::subspan

Synopsis

template< std::size_t Offset,
std::size_t Count = std::dynamic_extent > (1)
constexpr std::span<element_type, E /* see below */> subspan() const;
constexpr std::span<element_type, std::dynamic_extent>
subspan( std::size_t Offset, (2)
std::size_t Count = std::dynamic_extent ) const;

Obtains a span that is a view over the Count elements of this span starting at offset Offset. If Count is std::dynamic_extent, the number of elements in the subspan is size() - offset (i.e., it ends at the end of *this.).
The behavior is undefined if either Offset or Count is out of range. This happens if

* Offset is greater than size();
* Count is not std::dynamic_extent and Offset + Count is greater than size().

The extent E of the span returned by (1) is determined as follows:

* If Count is not std::dynamic_extent, Count;
* Otherwise, if Extent is not std::dynamic_extent, Extent - Offset;
* Otherwise, std::dynamic_extent.

Return value

The requested subspan r, such that r.data() == this->data() + Offset. If Count is std::dynamic_extent, r.size() == this->size() - Offset; otherwise r.size() == Count.